Hi, I Am A 61 Year Old Male. Good Health.

Hi, I am a 61 year old male. Good health. I take only take synthroid. Recently I have developed weakness and swelling in both of my hands between the proximal phalanges and metacarpal areas. Additionally swelling in my feet. Mainly on the bottom of my feet. Also, I have developed pain in my calves and knees. The onset has been pretty fast. All of this is within the last 4 months and symptoms are getting worse . To the best of my knowledge i have not altered my life style or introduced anything new that could cause this. I did have a small cyst on my middle finger at the cuticle removed. I was told that i had a bone spur that caused the joint fluid to leak and create a cyst. I was told that this is unrelated to what I am going through now. I have been tested for RA and Lupus with negative results. Doctors are stumped. I am having trouble walking. The pain and swelling are the same whether I do a lot of physical activity or take it easy. I was prescribed prednisone for 8 days but had no change. The rhumatologist told me I don't have RA and she cannot help me. Any ideas what this might be or what type of doctor I should see? Thank you.