I agree with these good folks. Educate yourself. Research the chances of actual death (as opposed to the cheap imitation kind) from the surgery. Honestly, the chances are very, very low.
On the other hand, the chances are very, very high that you will be healthier, be able to really walk, play with your son, go to school for meetings without embarassing him (or yourself) etc, etc, etc. There's a good like waiting for you.
Also, if you currently have high blood pressure or diabetes, chances are very good that those conditions will get lots better. I can tell you that my aching knees are much, much better, too. It feels so good to be able to walk like a regular person!!! That sounds silly, but you will see. I hope. Good luck! You are doing it for yourself and for your family, too.