Hive like bumps on ankle and hands not itchy anymore. pea sized mass back of neck under hairline kinda movable. leukemia or lymphoma all im 18 scared?

Hives are generally: itchy, but may not be any longer, if you're taking an antihistamine. However, this rash may not be hives; it is difficulty knowing without seeing it. The lump at the back of your neck is most likely a lymph node and likely not cancer....however, you really should see your doctor to check both of these issues to be properly diagnosed and treated.