Lots of good ideas for thought given above. My gut reaction is that you instinctively don't want the sexual relationship with your sweetheart to be "like" the other sexual encounters you have had.

Maybe it would be healing for both of you to talk, express how much this relationship means to you, and begin like newbies - with no expectations - cuddling - kissing - caressing without intercourse. Gradually allow the process to take over naturally, along with communication about how important you are to one another and what sex with each other means to you.

That may help 'reprogram' past experiences and validate that this time it is different.

Love is precious. Tend to your garden of love with compassion and it may bloom for you.

Aloha,
Jenny