it may or may not be rsd. it may be neuropathy. I've had rsd since 83, and have used methadone since 1990 or so, why do you say that's not good? It' works so well for me, and many of us. Ice, not so good. You may try warm water and Epsom salt soaks.
Rsd does Not need to present with discoloration, and all the other things other than pain. That yours gets better when you lay down is odd. Ask your neuro to rule rsd out.
I wish you the best!

Pete
asb