Antidepressants

Just found out I suffer from depression and a tiny bit of some psychotic thing. It makes me very selfish and sad all the time when my boyfriend chooses to go out with friends instead of me and I really don’t want to act that way. He deserves the best and I wanna be thy for him. For the past two months I have cried nearly every night and can’t ever be happy about the best things in life. My happiness lasts about a minute and then I’m back to my thoughts taking over. I’ve had a loss of appetite and I never want to go out with friends at all because I just don’t see the desire but I always want to be with my boyfriend. I just want to be happy again and was thinking about antidepressants I’m also 17 so I’m seeking advice from others that have taken it. Anything I should know before I take it, while I take it, or what will happen after?