No appetite

Hello ladies, I am a 19 year old female, about 145 lbs and 5”4, the past 2 months I haven’t been able to eat more than a few things a day. When I say a few things I mean they barely add up to 500 calories a day. I’m not doing this intentionally to lose weight, i think I look fine. It’s just like my body doesn’t want food and I don’t know how to change that. If I try to force myself to eat I get sick but I understand this isn’t a healthy lifestyle but I have no idea what’s going on, I used to eat plenty, as much as my boyfriend who’s 5”11 and 190lb. Any advice on how to get my appetite back?