Stamina (Problem)

Does anyone else's [male] SO have issues with stamina? Mine seems to have issues with being able to have sex daily and/or staying erect for longer than 10-15 minutes. If he tries to have sex for 3-4 days in a row or tries to last just a bit longer than normal, he tends to go soft and doesn't cum 😔 it makes me sad for him. (Low T isn't the problem)