I strongly urge you to get checked for infection. Your tongue sounds like it may be a yeast infection. You could also have a separate bladder and bowel infection. I would also recommend you get an HIV test
done since you are using the IV route for using and have what sounds like some opportunistic infections.
Your use of meth
for such a protracted period is concerning. You will certainly need help to prevent you from continuing to use. That help is out there, but you have to be ready to put it down for good.
The clumsiness, shrunken penis, metallic taste
, headache, erectile dysfunction
, and intense orgasm can all be explained by the effects of the meth and whatever its being cut with. Most of the time, these things will get better if you stop using. Bit the longer you use, the more likely it wont get better, only worse. Good luck to you.