Losing more than 300 hairs a day. 95% with a white bulb at the end. Hair gone from V. thick to V. thin within 6 months? TE/MPB?

If you have male pattern balding it would likely show the balding in a typical "pattern". Otherwise it would be just guess work.  You need to see a doctor for an exam.

To figure out the cause, you'd need to see a specialist who can ask you dozens and dozens of questions, examine your scalp and possibly order blood tests and rarely even a biopsy. One thing is certain - genetic hair loss is not the sole reason for your hair loss. Male pattern balding or "MPB" never ever goes from very thick to very thin over 6 months. Genetic hair loss changes just a bit in 6 monthsCauses of rapid loss include:1. telogen effluvium2. alopecia areata3. chemotherapy4. some scarring alopeciasPlease consider a full evaluation