Feeling kinda low? Anyone else with a similar experience?

I'm 24 & I finished university a few months back and have since been finding it difficult to find a full-time job in an area that interests me. I do work and have been trying hard to get something else but so far its been a no. I've always been a person who feels pretty low at times but have never gotten help for it,I never thought it was serious enough. I tried a few times (confiding in friends) but got sick of being told to pull myself together and that I shouldnt be depressed as I've never had any major life trauma, etc etc.. I've been a casual drug user for a while (literally just fooling around with stuff with friends during uni, like you do) though recently I've started using during the day on my own and getting high, sometimes before lunchtime, because it stops me feeling grim and gives me something to look forward to. I will even use a little something if I'm working that day to get me out of bed in the morning. I just feel reaaaaaaally impossibly low. It's like, you look out of the window and everythings so grey and your life feels like it has no meaning. I still see friends, please dont think I'm some stupid moron, I'm not, I left uni with good grades and I really really want to be normal with a good outlook on life. Some days I feel like I might be suicidal, some days I feel numb, most of the time I feel trapped and like I might go insane. I'm honestly not trying to be all dramatic and feel sorry for myself here, I apologise if it comes across as that, because I hate lifes whiners myself and technically I don't have much to be depressed about, I just am. Its frustrating. So my question is, does anyone else out there feel like this? What did you do to get help and how did you overcome it? & if anyone could provide any resources or support details that would be GREAT. Oh, & please dont just tell me to give up drugs, it's not as easy as that, use of them came about as a result of feeling low and not feeling I could admit it, not the other way round. At the moment, they're the only thing I look forward to. Sorry, thanks, I know this is long cheers for reading. If you reply, thanks for that too. :)