Blood spots, tenderness under armpit and pain in ribs. GP says it's a viral infection but I'm very concerned

I have got blood spots all over my body, i am very tender under my armpit my left hand feels like i have lost strength init , i have pain in my ribs .  my mouth is sore and very red.  I have been to GP and they said it was a viral infection, i am on antibiotics and steroid cream. but i am very concerned