I was wondering what people did to keep time in their head without a metronome while reading the more difficult note rhythms. I get it eventually but I find it hard to sight read new rhythms.

Practice and practice. The more sight reading experience you have, the more familiar you become with lics and rhythms. As far as keeping time on difficult licks, I always hear a drummer in my head who kind of fills in empty spaces and keeps the time going. If you can hear the jazz drummer, it will help you with your time.

Thank you, I appreciate the reply and that does make sense.

also this is more so folk lore but i like to sleep to the sound of a met. and i think it kinda helps me keep a steady tempo cause i am so used to hearing consitant time all the time lol. and you have to learn how to feel the music to keep time cause time, in my opinion, comes more from feel than anything else so learn to feel jazz ansd the swing and practice and it will start to come to u.