Pest problem.

OK, I'm at my last straw here and I don't quite know what to do, I've googled my problem very thoroughly for quite some time now and I'm at the end of my rope. I'll tell you a basic from end to beginning so that you can put yourself in the situation.

First and foremost, I need actual knowledge and explanations here, I'm not just gonna do any stupid shit you recommend.
So, here's my problem.

A while back I started cultivating some cannabis here at home, my initial set-up was bare to non-existent, I just started with the seeds basically and I've worked my way up, not having any disposable income has made this a scrounge and theft mission.

Once I had gotten myself some starter pots and proper soil I started by germinating my seeds to make sure they weren't bum seeds.
At the early stages they were kept in my window above a radiator (Not directly connected too, but an added extra heat but in no way near too warm, I assure you) where they stood to grow for some time, at this point they could have been any plants, so the shades weren't covering anything. They quickly grew up and everything was fine, they were all very healthy.

They had begun coming to the age where I knew they needed more air supply and wind to make sure the stem would grow thicker to be able to get bigger in the future, so I put them out, I don't know about you guys, but Sweden isn't usually all that warm. So, I suppose I was stressing them a bit, or rather intentionally hardening them to more harsh conditions than I'm sure they're used to.

Eventually they grew up to the point where it was super obvious what type of plant it was and keeping it on my pad wouldn't last, I have a walkway and a road just outside where I live, it's not super populated out here but I live in a place where during the summers, throngs of tourists are everywhere, so rather than being too reckless even though I still did it.

But it severely limited my ability to get them the light they needed, because keeping them outside I was facing a couple of problems.
One being someone seeing it and then either taking it if they're pro-can or reporting it if they're against.
So, I had to take them indoors, and realisticly, I can't deny owning them if someone saw them in my window, so naturally, my shades couldn't be pulled up anymore, even when they were, the sun hours at this time, isn't quite enough.
I had to pull them down and angle them, limiting the actual light they get, they still get light, just not directly anymore or as much.
Nor were they getting much more wind, open window can only do so much.

Note that I at that time didn't own any fans or lights.

Still keeping them in the window to make sure they at least get some light was my main priority I even resorted to manually fanning them from time to time.

Having not gotten them enough lighthours per day they were getting confused and some had already begun flowering, initially, they had all become female, I don't have a name for the strain, these are bought from a private person who couldn't remember. So I can't tell you what pH balance and care they do need, and they weren't feminized.
So now a couple had begun showing signs of male parts while still flowering. The lack of light had turned at least one or two of them into hermies.
Which I don't mind honestly, I'm just concerned for my babies, which are kept in the same apartment, and even though they are separated one can only do so much to not have them pollinate. Although I've heard having hermies kills of the chances of getting males and you also get feminized seeds from them. So it's not a big deal.

Now, as there aren't much of predatory animals or direct air supply I now faced another problem, pests.
I can't say exactly when they started showing up, but as the plants have been going both inside and outside they may have gotten something with them in, I know now for a fact that the pest I have is spider mites.

I'm not quite sure what to tell you guys about that, nasty fuckers, I, as soon as I noticed it began doing what I can with what little I have to keep it under control and try and kill them off, I read that they dislike peppermint and I also read about a brand of organic soap that contains lavender and such which I happened to have, so I made a mix spray and tended to the two plants that had the problem the most, obviously treating all of them to make sure it didn't spread, I had at that time very limited options in keeping them apart, I could only get light from one side of my apartment.

It seemed to have gotten killed off for a while, I got to them before they started making huge webbings, I only saw like a couple of strings between a couple of fan leaves, figured I was done, good riddance. Wrong.
I'll get to that later, while I was taking care of the main pest problem, the mites, the plants were kept very well hydrated to make sure they didn't have that dry environment mites like.

As I said before, no fans, no wind and open window wasn't doing the trick.
The water in the pots from watering takes longer to evaporate or be used because of this, lack of sun, means less water needed, lack of wind, nothing's drying it out. For some reason I don't have a fungi problem, but I've gotten these other annoying tiny flies which hover over the stagnant water and land on leaves with the THC and get stuck there, there's not a lot of them, but they're super fucking annoying and I'm not quite sure how to deal with that.

Now, I have lights for them, I have fans, but the flies still wont go away.
Minor problem, I'll deal with it by putting some sort of vinegar and sugar mix near.
But, since I got the lights they now have a more warm and consistent environment, meaning it's naturally going to be more dry and my big girl has gotten the problem back and it feels like it's on the verge of breaking out, right now I'm just containing the inevidable storm.
Only one plant has the problem as far as I can tell.

The plant has obvious mite bites a little bit all over the place, it's extra dry, even compared to the others, I can feel it just by touching the leaves.
I did find quite a lot of webbing near the base leaves, but that was dealt with, but I just can't seem to get rid of these fuckers.

I read that people can shower their plants to make sure that they rinse off all the mites, but I'm not quite sure if I can do that at this point, I'm worried, although THC isn't water solluble, I could probably still rinse it off.
The plant is floweing, it's not a lot yet, but there's obvious problems with me putting it in the shower.
Such as:
► Overwatering
► Fungi
► Budrot
► Washing the THC off?
► Possibly damaging the plant.

So now I'm reaching out for some assistance in the matter.
How do I get rid of these fuckers, can I shower my plant without killing of the reason I even have it in the first place.
Help, insight? Something, anything?