I'm sorry your T wasn't very helpful. Can you tell him what you said here? I bet the urge to "fix" is really hard to resist sometimes, but I know how invalidating that can be. But I think it might be easier for him to help you if you can tell him what you need from him.

I think it's a similar sort of thing with your professors in terms of asking for what you need. I imagine it will vary from class to class. For the class with the assignment, I might say that I am having mental health problems that are currently being treated, that I have the assignment, and asking if I can turn it in late. Is it something you can send as an attachment? Or drop it off somewhere? Late assignments are really common, and it's likely that your instructor has a policy for dealing with it that would give you a better outcome than not handing it in at all. For the other professors, it might depend on what the consequences are. If they have strict attendance policies, you might just have to take the hit and assume your performance elsewhere will compensate for it. If there are specific things you need help with, it doesn't hurt to ask if they have suggestions. Usually office hours were drop-in (at least when I went to them and when I had them as an instructor), so you wouldn't need an appointment. When I was teaching courses, I always appreciated when students were matter-of-fact about things going on in their lives and dealt with them the way you might do it in a workplace (i.e., not too much detail about specifics, not asking me to take care of them, but being specific about how I could help them be successful in my class).

I don't know if your reasons for being stressed when it sounds like you're actually getting okay grades are like mine. I actually didn't understand my reasons until recently, and I've been out of undergrad for over a decade now. But I do hope you can figure out how to cut yourself a little slack. Even if you get a B (or all B's!), the world won't end and you will still be a worthwhile human being. Please keep coming back and posting as much as you need to.

As a professor - I get students who have all sorts of things come up. I don't actually think that much about it. I direct the students to the dean of students for my part of the university and let them handle it if the student appears to be struggling across the board. If the student needs to withdraw/get some sort of medical leave or accommodation etc - it is not a big deal to me. I prefer not having to read a lot of reasons/excuses/things that are really not my business - I like the designated administrator to handle it -unless it is unique to just my one class.
I really suggest you contact the dean of students (or who ever is designated to take care of student issues at your university/college) and let them help you negotiate with the faculty since it sounds like this may be a bigger issue than just one paper or something like that.

Could you go and see the Dean of Students or the school counselor, and get that person to email your professors? An RA? Also, as a really check, having taught college English courses, I promise you are far from the only one missing class. If you feel like you can get to class tomorrow, turn your stuff in, and be a presence , they might notice your absence less than it feels like. So sorry you feel this way, bc academia can be a pressure cooker, In the big picture, the last time someone looked at my grades in college was probably twenty years ago. I think of how I stressed over those grades, but really the difference between an A and a B isn't much .