My boyfriend loses boner during sex HELP PLEASE

My boyfriend gets mind games during sex and loses his boner, he said it’s been a struggle for couple of weeks now because every time we have sex he thinks too hard about not losing it and then it just happens.. what is going on with him do any of your men have the same problem?? Please help me feel better I feel like it’s my problem and idk what to tell him how to fix this problem, he gets super sad about it..