One reason I wanted to reprint your letter is because it illustrates a problem that's all too common, I'm afraid: Most people don't plan sufficiently for their retirement years. They may plan financially for retirement, but then fail to plan on what they're going to do with the rest of their lives.
Did you make a mistake moving to a new part of the country? Not necessarily (although it would have been far better if you had prayed and sought God's will about your decision, as I hope you'll do in the future). But it would be a mistake for you to sit back and do nothing to change your situation. God knows your concerns and wants to help you overcome them.
What can you do? First, seek out a church in your area that not only can help you grow spiritually, but also has programs for people your age. (You mention elsewhere in your letter that there are many retirees in your area; many local churches probably have programs to meet their needs.) Not only will you meet new friends, but you'll also be challenged to grow in your faith.
In addition, seek opportunities for volunteer work in your new community. Your church already may offer some programs. Local hospitals or social service agencies may also depend on volunteers. Ask God to guide you; He isn't finished with you yet! The Bible says, "Therefore, as we have opportunity, let us do good to all people" (Galatians 6:10).