I need therapy but my parents will think I am crazy

Hi I am f(18) basically I've been really struggling the last year with my mental health mostly just because of school, friends and such but lately I feel it's a lot more serious. I feel sad all the time no matter what happens I always feel like shit and it has been really affecting my life and relationships with people badly. My parents always tell me that I change moods easily and that I don't stay upset for long but in reality i suppress all those feelings down until everything blows up at once and I unintentionally take it out on people who have done absolutely nothing to harm me and I hate myself for it. Also my parents always tell me that I don't eat enough and that i need to gain weight even tho i am a good weight for my age and height so now I don't have a good relationship with food because I eat-->gain weight---> hate myself----> lose the weight---> get yelled at. And it's honestly exhausting, I know they mean well and they just want me to be healthy but it just tires me to no end. I thought about going to therapy because all of this has worsened my quality of life and that therapy is just good for me in general but my moms family is very old fashioned and think that if I go to therapy then I am "crazy" and not to be taken seriously. I have seen this happen with my own eyes when my dad was on anxiety meds everyone in the family called him "crazy" my mom even cried to my aunt on the phone because he has anxiety. idk what to do I just feel so exhausted of living in general and I don't even have anyone to help.