I think walking is one of the most important physical abilities to feeling independent and capable, second only to seeing. So, I feel sympathy for anyone facing mobility limitations. With my best friend confined to a wheelchair and my own arthritis ending 30 years of running and hiking pleasures, I would not consider walking to be overrated. But, I would hope that even the setback of a fused ankle needn't stop one from still getting out, enjoying nature, and meeting people.
Jilldowney, your repeated posts of loneliness reflect a common theme on this website, with people trying to substitute social media chats for real life interaction and personal relationships. While I understand and partake in such online efforts too, I don't think they are the solution. We need live, face to face, interaction with other people every day, and we need friends to share and care. That takes courage and effort of course to get out of our comfort zone (home) and expose ourselves to public places, social clubs, or various organizations. With Oxford being a good sized city, I'm sure there are hundreds of social avenues for you there to pursue. You just need to find one that interests you and commit yourself to going - like going to a new school when you don't want to, but know that its necessary. This is one solution for improving your situation that others should agree with, but I'll add a second.
Your city has several churches, including a mix of good and bad ones, so I wouldn't suggest attending any of them without some proper guidance. But, I would suggest that joining a good Christian church that has a number of small groups is the best way of being welcomed, accepted, and immersed in good social interaction and friend potential. Christian or not, this is my prescription for lonely people. And if you're not a Christian, the exposure and influence of other good people just might give you something more to live your life for. In short, a church family can help you do better in this temporary, flawed life, while the Christian faith can give you hope for the new world and the incredible life that lies ahead for those who accept it. Go for the church family relationships now, and don't be afraid of what more may come out of it.
