DDug: you have done a great job ! My Mum 'gave us wings to fly' ;-).
What do U miss most about DS being around ? Surely not his laundry ;-).
Making time for yourself is important now. At least you are in contact. As Taz explained, when our age group left home it was usually to be married - I never lived in a flat or anything like that, DH went to Uni for 7 years and his Mum had raised him to care for himself. When we left to go on honeymoon I never gave a thought to how my parents felt!
Hobbies: volunteering: what floats your boat? We have a hobbies-type thread here somewhere as well as 'bookworm' etc., and exercise ....... could you join in the local school to support slow readers for example? Or a Scout/Guiding group in your area? It's a bit intimidating initially but if you offer up yourself you may be surprised! Let us know how you get on.