hello I am diabetic and on Wednesday I injected my insulin in my arm everything I thought was fine but Thursday night my arm got swollen very large and hard Friday it was hurting and red today I woke up it its hot and purple I am it looks like the worst sunburn now I thought it would get better it but idk what to do but I just noticed and this is way I am writing you my leg has a hard very red area just like my arm but I don't remember how this happened at all it hot and red it looks like a was burned and hard as a rock what should I do?