i'd drop the supps and see if that helps.
what exactly are you taking? any amino acids might be interfering with sinemet absorption in the intestine and crossing the BBB.

i'm always reluctant to take more sinemet but if you can take an amount that relieves the pain, that says something. remember, l-dopa IS AN AMINO ACID found in nature.
remember, what's important is how much dopamine reaches your brain, you have to figure out how to get a constant dosage into your blood and an adequate carbidopa level to keep all of the l-dopa from being broken down before it gets to your brain. i stagger regular sinemet with sinemet cr. my theory is take 100mg regular when i get up, let it saturate the enzymes that break it down, then 50/200mg cr 1.5-2hrs later, then 100mg 3-4hrs later to "top up", then either another 100mg or 200mg cr as needed depending on how functional i need to be in the evening. wouldn't it be nice if we had a simple l-dopa
blood test?
you have insignificant pain/rigidity in your fingers, legs, neck, back, etc?