Ouch!
No wisdom, but I share your off-road... ummm.... pains. Last year I tried to mtn bike more, but I kept crashing every time I went out. I got to where I had NO confidence on the mtn bike on trails and I stopped riding. This year I won't even touch my mtn bike because I'm afraid of crashing (again) and I know that will derail any road goals I have.
If I wasn't so accident-prone I might not have to choose between the two.