If you’ve heard of Headspace, Medito is more or less the same but run by a 501©(3) charity and is 100% free.
For anyone who finds guided meditation helps to manage their symptoms, or is curious to explore meditation, I can’t recommend it highly enough.
I’m sorry to hijack the thread, but have you tried brown noise (more like car noise than rain)? A bunch of people swear by it for making brain go quiet.
I’d doesn’t work for sleep for me, but I haven’t tried it for focussing.