You definitely will need constant reassuring. my bf keeps telling me "we don't do anything if you don,t totally want to" but I keep asking "it's fine uh? we don't have to do anything right?" cause I still feel bad about it. It's something in our minds that needs to be undone. You're lucky thought, as it's not the only relationship you've had. Mine was pretty much the first, so this is how I learned sex, to me it was how sex should be, and that why it took me so long to realize it wasn't right.
The key really is to think about yourself and only yourself. you may love that guy and want to make him happy, but you'll need to stop thinking about him. THink only of yourself, and see yourself as someone who needs to be taken care of, and you're the only person who an truely do that. Be good for yourself. If you don't take care of yourself, than nobody will/can. I find this is the best way to make sure you are not abused again, because when you really listen to yourself and take care of that, you notice the abuse and don't let yourself being done that again (of course, I do not mean that it was your fault for letting it be done toy ou, but I know that you may think "if this happened once, how can I make sure it does not happen again? how can I know if this guy isn't abusinve to me?").
This needs to be a constant state, not just for christmass.
Also, that will sound weird, but I've learned to be freidna gain with my body. by being abused, I developped a coping mechanism where my mind and body are disconnected, and it was hard to reconnect with my body as I let so many bad things happen to it. I have forgotten myself and promised myself that I from now on I will take care of my whole self and not let anything like that happen again.