I agree with Vickie, you may just have to rethink your strategy a bit. People with all kinds of disabilities raise happy, content children. It may just require some adaptation/planning. If it is too difficult to follow your baby as he crawls, then you can put up a gate and just let him crawl around that room while you watch. Outside, perhaps you can cordon off a section while he plays around you.
I had multiple back surgeries (and lots of pain) when my daughter was younger. I was never really able to run after her and play very physically. But I would sit on the deck as she played on the swing and showed me her "gymnastics" routines. I would sit in the driveway and be the drive thru clerk as she rode around on her bike and placed "orders." We read a lot, played board games, played dolls, watched movies, etc.
My daughter is now a well adjusted college student who is kind and compassionate. We are very close, most likely from all of that time we spent just talking together, lol. She remembers her childhood as idyllic, probably because she had what she most needed from me, my attention. It didn't matter what we were doing, what mattered is that I loved her, did the best I could, and gave her my attention.
It won't matter what you can or cannot do. All that will matter in your son's life is that you love him and you are there for him. If being "there" for him means being "there" from the couch, then so be it. You both will be fine.