Round Knots In Arms And Feet, Reddish Rashes With Tiny Blisters Above Fingers With Pins And Needles, Weakened Heartbeat. Any Thoughts?

Round knot close to/above vein in left arm, hands and feet have reddish rash above fingers and knuckles, from forearm down to finger tips feels stiff with a pins and needles sensation, fingers occassionaly develop a tiny blister that eventually becomes visually noticeable and after some applied pressure pop through to the surface, surging feeling in chest in synchronicity with heartbeat, which is weak and around 90-100 constantly. some major veins in both arms that are used to blast meth are constantly swollen. what should I do?