Hi I have lived on my own for many years and I also work from home. I should add that I live in a city far away from friends and family. Its far from ideal and I really struggle at times. Here are some of the tips which have helped me:-

1. Try to get involved with the locals (not students) too. You sound mature and sensible so you might find you have more in common with local young people who didnt go to Uni.
2. Check out http://www.meetups.com to find local socialising opportunities in your city. If they dont exist set one up!
3. On days when you are not meeting anyone then make sure you keep a routine like Inky suggested. For me this involves things like listening to local radio in the mornings. I love the local presenters. They are funny and help me to feel part of the local community. I also go for daily walks just to get out and mingle. It does help.
4. Are you a church goer? Attending local church services is often a good way to meet nice people.
5. Exercise is also important for your well being. If you are unfit you can start exercising at home but try to go to local classes too. A great way to meet new friends.
6. Keep busy and positive. This is the most important tip!

I hope these ideas help. If anyone has any other ideas please share them!