Too bad, Craig. I must say that people I know who have had back surgery continue to have problems, so I question the validity of such an approach in general. I would suggest that you avoid going under the knife again if you can. Get as much information from as many sources as you can before you do anything.
I have not had back problems like yours exactly, however, I possess lumbar #6 (10% of the population has this, and some suggest that we are extra terrestrials). This puts quite an arch in my lumbar spine, which could herniate, but never has. I had a great experience with a chiropractor after I had problems with my hips after the birth of my first son decades ago. He was very thorough and helpful with exercises for my situation as well. He took x-rays first (I know I know) and gave me such great insight to my spine; neck issues, the extra vertebra, etc. But you have to be careful who you go to, as I know people who have been maladjusted by chiropractors too. Get recommendations from clients whenever possible.
Exercise is probably the best remedy and prevention of just about every malady on the planet. In your case, I would recommend that you begin a yoga program along with some strength training, beginning with abdominals to help support your lower back. And I am not talking crunches with a plate on your gut. I am talking about really gentle stuff at the start. Lying supine and breathing with your abdomin to strengthen it will probably not cause any pain, and will support the back. Inhale and inflate, exhale and suck the muscles in double the time of the inhalation. Hold the exhalation with abdominals tight as you progress. Seek out an Iyengar yoga instructor in your area. As a former personal trainer and yoga teacher, I cannot say enough about this form of practice for anatomically and biomechanically correct movements. Iyengar yoga instructors have been well-taught in helping people with various conditions. You need to start a serious and dedicated exercise program to help your back (altough you may not feel like it now!). The upside-down poses will help you tremendously, but they will also have to be approached very gently. Iyengar yoga uses props to help students, and this is what you need. You will love it.
http://www.iynaus.org/Search/search.aspxYour job situation may or may not need changing. I have been active my whole life and I even have worked at jobs more strenuous than yours (try unloading and sorting packages for a major shipping company sometime and we can compare notes, as my back bothered me then from moving packages every 2 seconds). This situation is probably temporary. It may be your body telling you to work those abs to support your back, or to use better form when performing tasks. Where are the spasms at anyway?
I wish you well Craig. I think that you can beat this problem without resorting to drastic measures. But it will probably mean that YOU will have to change some things and work diligently to improve it. Soma and other drugs are really bad news, but I do understand that they may be helping you to ignore the problem. But they will not help your back in any way. They will numb you to it, and if you are not careful, you will resume activities and injure yourself further. Pain can be a good thing as it keeps you in line!
I will continue to exercise regularly. I might even reach 5th Dan black belt in my lifetime. We shall see (as you have to wait and train the number of years for which rank you which to achieve after the few years it takes to achieve 1st Dan - 2 years for 2nd, then 3 years for 3rd). But I do know that life is about living. I work hard and play hard. I hang out with people who do the same. The healthiest, happiest people I have known are active ones. I have a friend 40 years my senior who only drinks wine and coffee, but she works out daily, rides horses and just enjoys herself to the fullest <g>. My grandmaster moves like a 30 year old at age 68. These are my role models.
You are young, and you will continue to be if you believe it. That's what it takes. This is a tough situation. Injuries suck and we all suffer from them from time to time. Please take care of yourself.