I know how you feel. Thing is none of the stuff we think will make it all better does.
When I was young I was alone and depressed. Now I'm married, and I STILL get like you're feeling these days! Now, DH isn't the best at cheering people up (well not ME anyway.) so that's neither here nor there.
I think the key is finding out why we feel so bad and not letting others dictate our mood. It's hard and I haven't mastered it myself.
You can PM me if you'd like. If I don't respond right away I'm not ignoring you. I just forget to check it sometimes. But I'm available to listen ( read) to your problems.