I've asked the disability resource center here for additional help this semester-- I've missed entire weeks of classes, missed assignments, and missed exams. My person there gave me a letter to give to each of my professors explaining that I have a disability affecting my academics this semester, and offering some ideas to give me a chance to get caught up.
Tonight, I was supposed to take a midterm in one of my classes. What actually happened was that I talked to my professor and said that I wasn't prepared to take the exam, followed by explaining that I have PTSD that's been messing my life up this semester.
I've been avoiding talking to my professors until now because it's hard for me to ask for help. It's that social stigma that exists with mental health issues, compounded with PTSD making me avoid the situation entirely. I just want to be a successful student, I don't want to be treated special (meaning "I don't want to draw any more attention than is necessary, lest it be negative").
The result of talking to my professor is that I am taking the midterm on Tuesday morning, which will give me some time to study and get caught up on the material. The three homework assignments I've missed, I won't get any points for (but the prof will take my situation into account at the end of the semester). I have the rest of the semester to finish one of the projects I missed. And finally, my prof is going to scan her lecture notes from the weeks I missed so I can use them to catch up. I'll still lose some points, but I'll be on the same page as the rest of the class again and I can work forward from there.
Now, I have to repeat this with my other three professors. Joy. But the first one is taken care of. Small steps.
It's not easy, this asking for help stuff. It's hard to recognize that you need help in the first place, because the same brain you have to use to get help is the one that's giving you flashbacks and nightmares. So you're stuck, you're failing at school and possibly life, feeling like a snowball rolling downhill, and when the snowball stops you find yourself out of school delivering pizzas and asking what the hell went wrong. That's what happened with my first attempt at college.
I have never had a problem getting help at my university when I've asked for it. The asking is the hard part. So when is the right (as in, easiest) time to ask for help? The trivial answer is now, but my experience lately says that it might take time go get to a point where you're past the worst of what's in your head. You might not be able to get through the PTSD symptoms, and get brain and feet together to go find help. My answer is get help as soon as you can. If that means that it takes a week (or two, or four) to ask for help, then that's OK. That's the right time, when you're ready-- but don't wait forever.
If things aren't getting better, talk to your friendly neighborhood VA, call 1-800-273-TALK and press 1. Sometimes a person needs a plan before they can set things right.
One more thing: don't ever give up.