Low sex drive,pain and inflammation

I have 0 sex drive and it is causing issues in my 10 year relationship.

We have a toddler and both work full-time.

Another big issue we have is after my husband ejaculate , I end up having burning pain and inflammation. Every single.time. we have both been tested for any infection.

My ob a couple years ago suggested it could be altered ph balance and left it at that. This has been going on for a few years and I just can't .