Dear April

My apologies for replying you late.

based on you reply here are my thoughts of your problem

Your site of pain is mainly at the hip, you cannot lie down on it; usually we find that people who have this problem either have a pelvic fracture, a hip replacement or a greater tronchanter syndrome (bursitis, abductor tear etc) or an Wikipedia reference-linkSIJ problem (wherein closure/jamming of the SIJ causes pain as would happen lying on the affected side). In your case the above two can be ruled out leaving the latter two
You pain is mostly on weight bearing: this would suggest either a back problem, SIJ or hip problem
Sitting does not affect it...so we can technically rule the back disc problem out
YOu say the pain used to disturb your sleep but now you find you can sleep well; the inflammation you get from this problem is getting better...perhaps due to natural healing or the treatment you have been getting
you say you sleep better with a rolled blanket beneath you..this is puzzlying? (beneath you where?) if its your back...then it suggests that your back might be an area to assess again....
you are not experiencing any lower leg symptoms so I would not think you have you have a neurodynamic component (what people describe as sciatica)
You do not have pain when you bend forward but everything feels tight...Lumbar and SIJ seem unlikely, however what happens when you been backwards?

You have not provided me with any details with regard the test i suggested above, pushing your foot against the wall or what happens when you bring your knee to your chest

However here are my thoughts on your problem

while it is still vague what the primary issue might be..I would think from what you have said you have a possibly a hip abductor strain/ small hip rotator strain...an SIJ in/outflare could also be a possibility...

I think this because you say bringing your leg out is an aggravator, and lying on your side is also an aggravator....

I would suggest a few more tests that you could do by yourself or with someone assisting

Test 1
to check if you have an abductor strain
Stand next to a wall with your bad side to the wall, keep your feet pointed forward
now push against the wall with the side of the foot (stand straight and do not let you leg go out to the side)
what happens?

If you cannot do this easily from lack of understanding of my ridiculous description...
lie on you back, keep legs straight, ask someone to put their hands on your side of your thighs or knees, they should resist while you try to open your legs...there should be no movement of your legs apart with the resistance

Test 2
To check if small rotators have been strain
standing against the wall again...turn your foot out and push against the wall
repeat the other way....trying to push against the wall with your foot turned in...

there are other tests to for your SIJ but if this is the problem we do not want to aggravate it....

let me knkow how you get on...

cheers