Fifty year old is impotent, buys truck and motorcycle

My fiance who is 50 was diagnosed with diabetes in May, it is not under control, remains high. He has a history of a heart attack, high blood pressure, high cholesterol. He was on/off 20 mg of Lexapro, he went off of it in August for several weeks and his behavior was impulsive/bad. His Doctor put him on 40 mg now. I have two questions. He does not think any of these symptoms affects him and his decision making, and he has been making several big purchase items (new truck, harley, etc.) and he is also impotent, and has attempted to cheat??? Why does a man who is impotent do that? Thank you so much.

He wants to increase his self confidence and get away from the feeling of being old and ill.