I realize I got to this thread a bit late but here are two things you can do:
Pull-up negatives. Use your legs to jump up to the top of a pull-up position and then lower yourself as slowly as possible.
Banded pull-ups. This might be tricky to set up in a doorway but if you can, tie a resistance band at a height where you can kneel on it while doing pull-ups and the band will help push you up.
I realize I got to this thread a bit late but here are two things you can do:
Pull-up negatives. Use your legs to jump up to the top of a pull-up position and then lower yourself as slowly as possible.
Banded pull-ups. This might be tricky to set up in a doorway but if you can, tie a resistance band at a height where you can kneel on it while doing pull-ups and the band will help push you up.