I was on Ofev for a little a year before my TP (due to issues with my insurance company not covering it at all). I didn't really mind the side effects from the medication. The main side effect that I had was the diarrhea. Since I was able to control it, it didn't really bother me.
I understand about not being able to walk to much. However, keep walking as much as possible. Even when needing to use the oxygen, it is better to walk as much as possible.
It took me over two years to get back to work (partially because after my TP, I am still not able to take public transportation and I needed to find another job rather than take the 1 1/2 commute). I wish you luck.