In reply to gravity.time:
I wouldn't worry too much about muscles, they'll tell you when they're overstretched because you'll be really sore. If you're getting significantly sore from stretching it's probably too much unless you're being guided towards a flexibility goal.
I'd be more concerned about tendons. Stretching isn't the most natural use of the body, you're pulling your tendons into unusually extended/loaded positions in a way they are not used to, so I think you have a good chance to pull a tendon if you continue this compulsive routine.
It's good to listen to the body, it usually knows what it needs. But if you think you're perhaps indulging an unhealthy compulsion, it might be good to step back a bit.