Hip trouble

Attack/relapse 6 months ago and having a lot of pain in left hip. Can jut about weight bear on the leg - o.k when resting - if I exercise or walk (with sticks support!) it gets very painful.
Why? is it due to muscle tightening ?

Probably worth getting a physio to check you out and find the cause of pain.

Hip pain in adults - NHS (www.nhs.uk)

I have similar. It’s mostly concentrated around the SI joint. Not a MS symptom per se, but I regard it as a comorbidity, due to inactivity and muscle atrophy.