If I sleep to little like 2 hours I wake up feeling nauseous. If I sleep to much say 10-12hrs I end up with a headache and feel bad. Why is that?

Poor sleep. You may be sleeping for an adequate amount of time, but your probably not getting quality sleep. For example, you may snore. This can cause you to wake up with a bad headache. The nausea may just be a migraine phenomenom. I would consider seeing a sleep specialist.