Your premise is good, your execution needs work.
You should see a professional sex-therapist and work with them and your boyfriend. The issues you have >will get worse< over time with your husband if you do not both learn about your triggers and how to mitigate them and avoid them.
Otherwise, you and he will inadvertently trigger memories over & over again until you develop an aversion reaction to sex with him - the horrible emotion you feel about your past will automatically trigger at the thought of sex with him. It's just how it happens and is well-neigh unavoidable.
It's not necessarily a quick process either, things can seem fine for several years and marriage seems to be a catalyst as well.
Reborn celibacy until marriage is not sufficient to help you with this trauma - it is avoidance which just buries it to resurface another time.
Starting-over on your terms is very good; postponing starting until marriage is not.
Sex starts with kissing and finishes with intercourse.
Starting sex and refusing to finish it is inequitable.
He'll think it's "great for you" for a few weeks then you are going to find him more and more irritable, or avoiding you, or spanking it to porn all the time, etc...
It will ruin and end your relationship.
You need to work on healing now not later.