My fiancé is 38 we have a great sex life but lately when we play he has not been getting really rock hard and sometimes he only cums a little bit rather than his normal amount which is heaps my question to you's is if he's not getting rock hard does that mean he's not really turned on by me and attracted to me? He says its not me but I can't help but to feel like it is me

If he is having physical changes such as the amount of ejaculate, he could be having medical issues. It means it 'isn't you'. It is time for a trip to the doctor's office for a check up.

If he gets a clean bill of health, then look at other factors such as stress, exhaustion, diet, exercise, sleep patterns, distractions, etc. These and more can cause issues and are more common than disinterest.

Of course you should also be paying attention to the rest of the relationship, too. Are there any other changes in his behavior outside of the sexual aspects that might be a cause for concern?

No other changes to his behaviour that I have noticed...

Then he needs to get a check up. Erectile problems can be a symptom of other medical issues such as blood pressure and Diabetes.

If nothing else, it's a place to start and hopefully get some concerns out of the way. That in itself could help.