I think that I can understand what you're saying/feeling. I have felt that way, and do feel that way, at times.

Maybe it's because it's so hard to put ourselves out there, while depression likes to make us stay isolated, and then we actually have fun...yet we can't help but think of all of the times we've been burned by "friends" or loved one's when we've let our guard down. Maybe we're used to the "bad" times always following the few good times that we have, and it's hard to stay happy then?

I don't know if what I'm saying makes any sense or not. My tired brain has a hard time working right now

I hope that you feel better, and that you can go have more fun times and enjoy them at the time and afterwards.