The red skin could be roseca. My mom has it and sometimes her face looks like a cherry. Stress is a cause of hair loss.
Have they ran tests on you? Blood tests are very conclusive. My brother is a doctor and he always says you can learn so much from blood tests. He also swears by vitimans, vitimans, vitimans.
Have they testsed your stool? If you are seeing things in your stool and they don't think it's a worm, perhaps it is something like mucus. This can appear as tape worm segments. Perhaps you could have digestive issues - mucus can be IBS. Usually not anything serious.
If you continue to worry, I would ask for a stool test. All the doctor has to do is order it. You can take a cup home and return it to the lab. It's not a big deal so they shouldn't fight back about it too much. If you still feel like they aren't examining you enough, go to another doctor.
God bless and try not to worry so much. Everything will be ok!