Woman at my work started taking anti depressants and she just turned into a overly talkative, smiling idiot
I think they just take the edge off of your mind and open you up to communicating/interacting/talking, get your mind from its self deprecating cycle of doom.
Like a "few" beers or smokey things do to "normal" people.
She would often repeat herself in conversation but id pretend to no notice
The dudes absolutely depressed but i think if we are honest most of us have been there, especially computer forum losers... most people here have issues physically or "mentally"
But getting to the age of 40 and still not having a clue or doing the social norms like having family and kids (i included myself there) is truly deemed as failure by most modern standards...
Without the drive of supporting a family or partner or anyone? (get a cat)
You will find, like you have, you really have no point in existing. Youre a zero contributor to society or the future of humanity. (mostly like me too
But i do go on holiday 4x a year and enjoy life more these days after moving here to Sweden)
I think if you are single its compounded 10x worse. You should find someone in you're life to share your misery with... Seriously it is hard but you must have something in common with a man/woman whatever your preference is....
If you have no friends/family then as others suggested you will need to go down the NHS route and it wont be fun or easy but you need a kick back onto the rails. If you do wanna change..