I know exactly what you are going through.

Ihad spinal fusion of l4-s1 still have the 6 screws and rods in my back.

The best thing I can advise you is to do plenty of walking and swimming and not only while you are healing but the rest of your life.

I still walk 5 miles everyday and am able to go to the gym atleast 4 times a week.

If you do it right it should not effect you at all, my current job is physcial and I have no adverse effects from my back.

What happens from here on in is up to you and like I said if you do it right you will be able to lead a good activelife.