@Stunnershaz
Listen, you're doing great! You've told your mum so you've gotten support. You have a solicitor appt to get legal advice. Mum has a place for you to go in Jan so you have a way to get out. Those are the three main things.
All you need to do now is to be as 'normal' as possible, carry on and keep quiet. Yes, give him the Xmas gifts, not to do so would not be 'normal'. If he says he's 'working late' or 'meeting friends' just wave him off as you usually do. Remember that when he's not in the house, you can 'let your guard down' a bit and let yourself 'feel what you're feeling'.
I know your mum is upset and probably frantic, but impress on her that 'carrying on as normal' is for YOUR safety, not for his convenience.
Be aware also, that if your STBX is guarded enough about his privacy that he has a safe you're not allowed the combo for, he may also have some type of camera in his 'office'. Now, it may be that he's so sure he has you 'controlled' and is so arrogant that he doesn't think he needs one, but it's something to think about.
It's mid-Dec and you'll be out in Jan. What with Xmas the time will fly by. Soon you'll be free.