If you are home bound, or find it difficult to leave your home, then you may qualify to have a home health agency and/or a Durable Medical Equipment (DME) company help you.
What you can do is try calling a DME and/or a Home Health agency. They will help you to find a doctor. The home health agency or DME can recommend a doctor that they already work with in your area. You may have to see them one time, but it seems that at your age you should have medicare/caid. This is also something that the home health agency can help you in obtaining if you do not already have it. They will help you with the forms to fill out.
You may want to call the DME company first, and they may recommend a home health agency if that is something you need (to have a respiratory therapist or RN assess your condition and needs) You may have to try both. You can find one in your area by looking on line or the yellow pages.
Let me know if you need help with finding an agency in your area. When you call them simply state that you require oxygen equipment and have trouble getting to the VA to get a prescription.
Again, reply to this post if you have follow up questions or if you need me to look for agencies to call in your area, please provide your zip code.