Hi there, So sorry tohear your symptoms are giving you hell.
Sleep is a major problem for most people with anxiety you either cant get enough or you get none at all, Insomnia is evil. As for the inner tremors feeling like your trembling or shaking i get that all the time especially when when my anxiety is interfereing with my sleep, in times like that i make sure i have a nice warm bath before bed some camomile tea (no sugar just a tiny bit of honey of you like it sweet) and make sure my room isn't hot or too warm just comfortable and i do relaxation exercises in bed (tense and relax starting from my toes right up to my shoulders while doing breathing exercises) this seems to help with sleep (i also take medication for sleep but i prefer then non medicated sleep).
As for the derealization cuch is right it comes in waves there isn't a cure for it but it can be managed through therapy i.e mindfullness or CBT these types of therapy can help the thoughts and weird feelings so maybe look into that.
I hope some of this helps a little bit. Keeping a sleep diary and keeping to a sleep routine is a good way of regulating your sleep, making bed time more relaxing than anxious. No harm in giving it a go and if you still feel its giving you issues talk to your Dr, phsychiatris/psychologist/ therpist about it (thats if you have a pdoc). but talking about it and letting the emotion out is definitly key to keeping bedtime a safe happy place than a worrying one,
Good Luck stay well and I hope you feel better soon