Missing online lessonsWatch
Send her an email explaining what happened with your anxiety and stuff and your problems accessing the site.
Ask her if she can help fix these problems.
Send her a study plan of how you are going to catch up so that she believes you are committed. This will also help you to catch up a bit even if not all.
You don't have to do all of the work just some of it.
Maybe ask your classmates for their work (idk what your subject is but hopefully it is one where this is doable).
Its going to be okay. Just take a deep breath.