I accidentally fell asleep with an ice pack on my shoulder. it's bruised with a huge blister and some smaller ones. it's tingling and feels warm.

Frostbite : This thermal injury sounds like frostbite to me. I think you need an urgent evaluation at a burn center. This sounds like third or possibly even fourth degree frostbite. You also need to update your tetanus vaccination and possibly be placed in a hot whirlpool, get debridement of dead tissue and education on dressing changes and follow up with a burn surgeon. This is Advanced Trauma Life Support