Being lonely, feeling anxious, depressed even feeling angry - well it sure aint fun and one of the characteristics of all this is the obsession with constant thinking about negatives. I'm sure some won't like this but dwelling on how bad it is won't get you anywhere. You have to fight, you have to decide you've just had enough of it. You are not worthless and without hope but you have come to believe you are. Do take any help that's offered and try - but only with medical advice to come (gradually) off the meds if you've become dependent and they are turning you into a zombie. Keep busy! Find something to do that absorbs your interest and takes your mind off your woes; surprisingly you might find you haven't thought about your problems for a few hours. Me! I play guitar, write songs, make things, read a lot and follow my interests in art and history. Interestingly I've even met a few folk and joined the odd club through these interests.
Now I'm certainly not saying it's easy - I'm not out of the woods and not "right" and probably never will be but I've been down the deep, dark bottom of the pit and I'm way better now.
But here's the hard truth and please feel free to shout at me...... You cannot rely on medication or doctors to cure you. Ok, they help but in the end it has to come from you; you have to fight, you have to make an effort to see some positive and celebrate any and every small achievement you can.