Was he talking to her before we split?

I’ve posted recently about how I found “dude wipes” and a child’s press on nail (wasn’t my children’s) in my Tahoe, suspicions that he was using the personal wipes to clean up himself in the car....

well my husband and I haven’t been doing good lately and he just recently told me about a week ago that we “need to start seeing other people” in a fit of anger....but things took a turn for the worst last Friday when I was planning an IUI cycle (cost me about 1,200 for meds etc) and it was all planned out til I came home that morning from work and he refused to follow through with the appointment and we got into a big argument,

he left and had been gone for days he posts up on his Facebook a picture of his child at the beach with another woman I’ve never met before, he also changed his profile picture when it’s been the same for years...says she’s just his friend but I’m reluctant to believe that...I need an outside opinion...am I crazy here??? She’s the reason he’s acting like this, he needed an excuse to separate so he could pursue her...