I had to do something similar the other day but it is the right thing to do. I do not have much contact with this man and it would kill me if he were dating, but I think he should - I just don't want to hear about it.
The young man you were seeing needs time to grow up. I am 43 and would not feel comfortable dating someone so young either. I'd always wonder if he needs a "mother figure" or something, kwim? Life experience has taught me that it takes more than just love to make a relationship work. That's my opinion anyway.
Be strong and comfortable with your decision. Hang in there!