I have back problem and I cannot kick high also. In fact I injured my back last week and looking for a doctor right now. If I were you, I'd go with BJJ, just start slow, let them know your condition so they go easy on you.
I am not familiar with the two you practiced, they sound like striking art. BJJ is proven to be very effective. Not for anything, you'll go a long long way just learning the take down defense.
Definitely not TKD. I had a few years in TKD, that's what injured my back. TKD has a lot of kicks particular high kicks, there's definitely a ceiling if you cannot kick high or kick too much. It's very hard on the back, I am a victim of TKD.
I would not drive an hour to class, I would just compromise and go to BJJ...........Hell, it's NOT a compromise in my book. It is about the most effective MA.
You look into non traditional ones like MMA? UFC gym seems to be popular, we have one like 5 min drive from me. They have classes. Or you only want traditional martial arts?