TTC with a BF who has a low libido?? HELP!!

So I’ve been in a relationship with my BF for over 4 yrs. I’m 31 and he’s 39! we’re both finally ready to start a family but he’s libido is verrrry low! We hardly have sex anymore. He said he’s definitely up for having a baby but is worried about his lack of libido and therefore not being able to have enough sex. He got his testosterone levels checked and they came back normal. I’ve been checked out too and apparently I’m fertile, as in my hormones show I do ovulate each month. Does anybody have any advice on what to do when TTC when BF has a low libido?

Also I recently found out that when he was younger (baby/toddler age) he’s testicles were undescended and had an operation to fix them. The Dr told his parents that this would not affect is fertility. BUT, I can’t help but wander if he is even fertile??? I question this because I know that he he’s had ALOT of girlfriends in his youth but never got any pregnant. Now I know he’s promiscuity with no unwanted pregnancies isn’t a reason to think he might fertile BUT, I can’t help but wander. Ahh my mind is racing all the time. Please someone help me lol!