please help me with sever tense post malasya extertion after activity

hi, i feel exhausted all the times. if i have bed rest i feel a bit better but if i try to do a bit more activity i get sever tense insomnia and the next day i will be suffering from sever post malasya extertion. why? i know a lot of people with cfs that does not suffer from that extremely heavy exhaustion the next day. would you be able to advice in how to minimize the impact of the activity in my body? do i really suffer from cfs or ms? how should i treat this symptom as the doctors are always ignoring my extremely bad quality of life and pain.