What Causes Itching On Legs And Bruising?

Hello. I am 48 years old, 5'9", 180 pounds. My general health is good but experiencing severe itching in both legs for the past year (not relieved by OTC creams). The itching feels like it's inside my muscles/bones...very deep...the scratching has caused bruising. The only thing that helps is a strong sedative antihistamine recently prescribed by a dermotologist. Lately I have a very stiff neck and smallish (approx 1 inch, maybe a bit larger) soft, painless lump above my collarbone. Also recently tried to give blood and my hemoglobin was too low. Should I be concerned about Lymphoma? I have an appt with my GP this Friday and I need to know what to ask/do.