You asked so I’ll come right out and say, yes, this is ridiculous. Frankly, you have no way of knowing if he’s a great guy. You only know him from the best self he is portraying online. Further, I have to wonder why a man who is so terrific is talking online to a 17-year-old instead of finding women his own age to be with. Of course your parents wouldn’t approve! He’s old enough to be your father, he lives alone and he’s trolling for young people on the Internet. None of that will impress anyone who cares about you. Actually, it’s scary.
I’m sure having someone interested in you is a wonderful feeling. I’m equally sure this is a dangerous fantasy. At 17, your stage in life is to be finding out about yourself in relationship to others in the same stage. Any time you are spending with this guy online is time you are not hanging with friends, dating people, and being actively involved with real live people in the real live world of your community. Please, thank this guy for his interest, if you must. Then change your email address and move on.
I wish you well.