My (22m) gf (22f) doesn’t like seeing me happy

Me and my girlfriend have been together for a year and 10 months, recently she told me “I hate your positivity sometimes” after I told her to just try and enjoy some time with her family over thanksgiving. She has said things similar to this in the past and she has even said that she wished I didn’t love her before. I’ve been with her so long and feel like I have my life kinda planned out around her. I’m a senior in college studying environmental engineering, she just graduated last semester and is waiting to see if she gets accepted to vet school. She deals with depression and I have known this since the beginning of our relationship, I try to keep her mood up the best I can but if she doesn’t even like to see me happy I just don’t know what to do. One of my biggest fears is that after I graduate I follow her to vet school just for her to realize she doesn’t want to be with me and then I’m on my own in a place I don’t necessarily want to be. She tells me she loves me and that’s great, but I worry that she doesn’t actually like me if that makes sense. Anyone dealt with anything similar? If so please provide some advice.