As you've discovered, a city can be a very lonely place. People get involved in their own activities and careers (as has happened with your husband), and it isn't easy for someone in your position to meet new people or find friends.
This is why you'll need to take definite steps to overcome your loneliness. How can you meet other people? One way would be to get a job or take a college course or get involved in some other activity where you'll be with people (if you don't have family responsibilities that would make this difficult). You may find some of them are just as lonely as you are. But don't get involved in something that won't be uplifting.
The best way, however, to make new friends would be for you and your husband to get involved in a local church. Elsewhere in your letter, you mention that neither of you comes from a religious background, but why not start your journey of faith now? By a simple prayer of faith ask Christ to come into your life, and then ask Him to guide you to a church with programs and activities for people your age.
But a church will not only help you meet people. Above all, it will help you grow in your relationship with God. Could anything be more important? The Bible says, "Grow in the grace and knowledge of our Lord and Savior Jesus Christ" (2 Peter 3:18).