Jimmy,
First of all, I'm sending a cyber hug your way.
Your story brings tears to my eyes as I am able to relate to it so well. I have had 3 back surgeries and have not been able to work for over a year now. At times the pain controls me.
It's so easy to get down in the dumps when feeling so much pain and experiencing feelings of worthliness. However, it's important to realize that even in pain and when facing so many challenges, life is far to precious to waste on such negative feelings. Life is a gift given to us by God to enjoy and cherish.
You have a choice to make and I'm not saying it's an easy one. You can either wallow in self pity and be miserable, or you can accept the blessings of the circumstances you have been dealt and make the most of your life. Depression sets in when we see our situations as being hopeless. You need to be the one to decide to give yourself hope for the future and put meaning into your life.
So how do you do this? First of all, figure out what your can do and don't focus on what you can't. For exercise, even if you can't walk well, there are leg and arm exercises you can do while sitting or laying down. Exercise is critical to our emotional and physical well being. What hobbies or activities to you enjoy? What social activities are you involved in or can you be involved in? Surrounding yourself with others that can relate to you is really helpful - get involved in a church, a pain support group, get to know your neigrabroadors, etc.
For your weight, realize that if you can shed some of the weight you and your back will feel much better. Talk to your doctor about options for weight loss and consider joining a support group for weight loss. When we are accountable to others our ability to reach a goal dramatically increases. Even if you were able to lose a couple of pounRAB a month the positive feelings you would experience would be incredible.
Figure out what makes you happy. Many people here on this board have found that helping others cope with their pain problems have given them purpose and made them feel better. You are in a unique position to be able to help others with similar problems because you know what it feels like to be there. You may have hobbies that you enjoy and can do that you could share with others. In any case, give yourself hope for the future and a purpose for getting up every morning - you deserve nothing less.
For your back pain, if it's so bad that it's got such control of your life, get to a spinal surgeon to see if there are options to improve the pain. There may be surgical or non-surgical options to bring your pain level down.
I'm not trying to minimize your pain in any way and I'm not saying that making changes is easy at all. I have found myself getting down many times, even recently, and have had to pull myself back up. I, however, have had to be the one to pull myself back up while leaning on others around me, including the people on this board. We're here if you need to lean on someone.
Take care of yourself!