Hey onwards! Well I wouldn't necessarily recommend others go the DIY route - it has been a mixed bag for me -
I think I was lucky because I am young. My ability to exercise is good but not incredible. I can ski pretty hard, I can weight lift, but my endurance is still not all the way back. After a game of basketball for example I have a hard time breathing and can only really play 1 game. I usually don't sleep well after exertion either. But, I am gonna go on a 4 mile bike ride today, which should treat me just fine as long as I take my time.
A mistake I made was not cutting back on the exercise enough, it has definitely slowed my progress overall. But gentle exercise like bike rides have been really good for me.