I feel you! Once I moved in with my boyfriend I started getting these same thoughts
I 100% feel. We have been engaged for a while now, and we are moving in together soon, and I’ve been ruminating on this a bit.
Two things. 1) What if he had OCD and was asking you to still love him. Would you? Of course you would still love and support him. 2) You can improve and you will improve with time. My OCD was hardcore when I was young. Now, at 50, it has faded off quite a bit. If you guys get married, he will be with you in the future, when you may also improve. Your future can inspire you to use your tools and methods for meeting the challenge of your OCD.