I didn't actually tell my boyfriend until months after we got together, so can't help with that side of things sorry, I think I was still sort of in shock as I met DP a couple of months afterwards so still very soon and I hadn't really addressed it.
Looking back I'm surprised by how unaffected I was when we got together, I would've expected to have had a much harder time. I think perhaps subconsciously I felt comfortable going on a date with him because he looked nothing like the man who raped me, and he doesn't actually fit my normal 'type'. He was also very gentle and calm and relaxed, and to this day the angriest I've seen him is when he got stung by a wasp.
I only told him when I got pregnant, as pregnancy and the interactions with other people and emotions that come with it threw up a lot of things I hadn't addressed since it happened. He was very upset for me, shocked that he didn't know for so long, and wanted to know if there were things he should or shouldn't do during sex etc to make sure I continued to feel safe.
There was only one time I had an unusual reaction, and it was when we were cuddling in bed and he had my leg between both of his and just squeezed it. It wasn't particularly hard, but I was suddenly filled with such fear and a feeling of being trapped which completely took me by surprise.
I would say go slowly, be patient with yourself, and trust that if your new boyfriend is kind and lovely and trustworthy then he will be slow and patient and gentle with you, and let you set the pace and what you're comfortable with. You don't have to go into details all at once if you don't feel comfortable with it, you could just say that you've had previous unpleasant experiences with an ex and so want to take things slow/don't want to do X or Y etc.
I hope you have a safe and wonderful experience getting to know your new partner 