Figured I'd Ask Here Too

I'm writing a story about two girls who fall in love. The main character is lesbian, and the love interest is bisexual. My question is... what sorts of things should the MC go through with her sexuality that would warrant a depression diagnosis? She's already accepted her sexuality, so that won't work. If it helps, her father is a real bigot towards LGBT+ rights. The only ones that really know about her sexuality are her mother and a few past friends she's had as well. I know that could be a good reason for her dealing with depression, but I need other ideas though.

I decided to post it in my blog because I know I'll get better results that way. So, I hope you guys can maybe give me some insight on this. Perhaps, if you are lesbian yourself and can provide me with some ideas and such. ^^ Thanks, if you do. I just want to make this story as authentic and realistic as I possibly can.