Post Thrombotic Syndrome?

About 9 years ago I was told I had 2 to 4 blood clots that travelled up to my lungs and landed there(over a 2 week period). All the drs can presume from thier many different tests was that it travelled from my left leg (because there was alot of vericose veins). But no "disorder" was found.
So back to that day 9 years ago when I landed in the hospital short of breath (but no other symptoms). I was started on an daily injection called "Fragmin" for the rest of my life to treat this thing and make sure it doesn't return because no reason found.

So here is the problem.... within one week of that day at the hospital, I got the deepest PAIN in that left leg which has become worse each passing year. The pain is very much similar daily to a 'tourniquey' being placed on my upper thigh and another around my knee. The pain only begins to subside as I lay down. 'Sitting' makes it worse as well because I am bent at the hip and knee. The whole leg must be straight(and somewhat raised) to relieve the pain and swelling. But who can live laying down and not even sitting??? I use a support stocking to keep me upright for maybe 30 minutes at a time. Without the support stocking I only have a minute or 2 upright.
I have been to many drs and a couple of hemotologists, but they don't even understand what I am saying because there is minimal 'outward' signs(damage) ...such as being overweight, purple discolored, disfigured super swollen leg. That, is what they say is "post thrombotic syndrome".
I am so tired of this . I can not longer do ANYTHING that takes more than 30 minutes. So my life has been reduced to living off my couch and watching tv. No more working, shopping...nothing .
I am so hoping there is someone else that understands, and knows what this is!
Thanks for letting me rant.