Yes, exactly spot on. Did it occur to you maybe he was doing something he wasn’t ready to share or maybe he was cheating you will never know.
I had a cousin who was committed to a facility. When I went to another town to visit her a guy I was dating asked where I was and I lied. I didn’t want to say I was visiting another town to check on my delusional cousin who was a threat to herself and others. He found out I was out of town and jumped to certain conclusions just like you have.
You never know until you act like an adult and ask