For what it's worth coming from a stranger on the internet, I like what you got. That'll definitely get your players motivated to be on the defensive and to maybe think a little more strategic. I can see a bloodied character, if they aren't careful, slowly being sucked into a death spiral that is difficult to get out of. I like the use of exhaustion levels while dying as well. Being brought low should have a lingering effect. My only concern is that it may make the players overly cautious and too afraid to engage the enemy, which might make things boring. Maybe not though. I will also echo that not being able to heal without rest once bloodied is too much.
I've been using 5E Hardcore Mode rules for dying and it's made being at 1 HP a lot more nerve wracking for the players. The rules go something like this:
- When a character is knocked to 0 HP the character is unconscious and bleeding out. If no aid is given in 3 rounds, the character bleeds out and dies. A character is no longer dying if they receive 1 HP of healing through magic or medical aid (I use healers kits as a one time use item that allows a character to expend a hit die to regain HP)
- A character dies if they take 10+ points of damage past 0. So if Johnny fighter is sitting at 1 HP and takes 11 or more points of damage in a round, he's killed. No saves. Straight up worm food. I had a ghoul slap the lower jaw off of the cleric. It was great fun for all.
The supplement also has a rule for becoming injured that reminds me of what you've done with being bloodied. The condition gets triggered if you take 10+ damage from a single source and are still standing. Much like what you have done, its the start of a death spiral that can escalate quickly if not dealt with right away.
PS: To anyone looking for a more deadlier game I highly recommend 5E Hardcore Mode.