Is it okay to give up?

I don't even know where to begin with all of this. I feel like it's been months since I've enjoyed a workout. I'm exhausted. I feel so emotionally withdrawn from everything. No matter how hard I try to stay calm and relaxed, every little thing continues to irritate me beyond belief. I snap at my loved ones constantly, I'm a terrible friend, and I feel so selfish because I just can't seem to be there for anyone else at the moment. I haven't had my period since April and I just feel cold and uncomfortable (bony, kind of) all the time. I can't stop counting calories and using exercise as a way to "earn" my food. I wake up a half an hour early every morning so I can go for a walk just to get my steps in for the day. If I don't work out an hour everyday at least five days a week I feel lazy. "Rest days" (which normally equate to me doing a lighter workout or walking an extra few miles) give me anxiety. I feel like I'm drowning. My whole identity has become "the healthy, skinny one" even though I don't feel healthy at all. I weighed myself yesterday and freaked out when I saw "116" on the scale, even though that's considered underweight for my height.

I don't know what to do. I just feel so overwhelmed all the time with everything that I'm trying to juggle. No matter how well I do in school it feels like I'll never be good enough. I just want to be done attaching my worth to how I look or how intelligent I am. On good days I know that I'm more than all the superficial stuff, but then I get stressed and my self esteem plummets. I just feel like it's so stupid for me, a 19 year old, to be struggling so much with this stuff. Shouldn't I know better? Aren't I old enough to deal with my problems myself?

I just feel so broken. I'm so sick of comments about my body. I'm sick of hearing or thinking of the world "calories." I'm sick of being told that one of my family members stepped on the scale and lost weight because they were "good" this week. It's like I'm jealous, but I have no reason to be.

I have no idea who to talk to about all of this. It's so hard to type all of this stuff out, let alone say it, and I feel like none of my family will understand. I know this post has been a jumbled mess, but I just really wanted to get this out there in hopes that some of you might have some advice for me. Literally any tips whatsoever would be greatly appreciated. I really don't want to waste my life away feeling so crappy all the time.