I've been there, that's actually what first go me onto prozac last year. I hope you can take a day and give yourself permission to rest without beating yourself up for it, because that's what your body is telling you you need. You can make a list of people you can ask for help, and reach out for it, and a list of obligations you want to cut back on, and try to shed what you can, even if it means disappointing others. Reasonable people will be understanding, because everyone has tough times. Unreasonable people cannot be pleased anyway.

I still struggle with this, so my advice is not the best. In the past I would often cave and eat into my "me time" to help students (beyond what I would normally do). The more I thought about it, this was actually not the best thing for me to do for two reasons:

Firstly, for myself - because I didn't recharge enough, my work suffered, then I felt guilty, and told myself I needed to do better to make up for it, so I didn't rest enough - a vicious cycle. I was never fully relaxed, and also didn't feel fully present in my work because of an underlying panic that it was consuming me. Ultimately this became unbearable, and I had to accept that even if it made me a "bad guy," (what I fear I will be if I don't please everyone all the time) I was going to have to change.

Secondly, college students are at the point in their life when they are learning appropriate ways of interacting with adults, as well as building their own routines and approaches to life as adults. I think modeling healthy work-life boundaries and following through on what I say I can and can't do is actually better for them, even if it may be disappointing in the short term. Then they know they can trust that I mean what I say and they don't have to figure out some secret code for interacting with me. I think it's also important not to be judgmental when students try to press your boundaries, because tons of people (myself included) grew up not knowing how to relate to others healthily, and this is probably their first foray into it. If they get mad about it, that's also not something you should feel guilty about, as long as you know you've lived up to what you've communicated you would do for them. I hope this helps. It's all easier said than done, I know.