I understand the financial aspect, I'm kind of in a similar situation with my neck. 6 weeks is very conservative, your recovery could take much longer.
Take Care
I have done 3 injections, physical therapy and pain management. Nothing seems to work. The nerve is obviously damaged and the doctor says the nerve is being compressed and may not heal as a result. It sounds realistic to have the fusion to relieve the pressure on the nerve but I'm worried how this will affect me financially. It seems to take approx 6 weeks to get to a point where your recovery becomes apparent. I need to be out of work for the least amount of time as possible.
You've probably done all the conservative stuff right? You don't want to let this go to long, it will take longer for the nerves to regenerate and it will make your recovery harder.
The recovery from this is going to be a little lengthier than for your micro, walking and rehab are really important. I had a fusion at L4-5 eight years ago and It took a while to recover, but I haven't had a problem with my low back since.
Take Care