Earache from headphones?

I've been using my huawei headphones for a long time and I'm actually satisfied with them, but I've often had pain in my ear after using them, and I've just noticed that my left ear is completely red from the inside. Is that normal? What can I do about the pain because I can't lie on my side because it hurts even more.

That is certainly not normal. There's not much you can do about that. You might have to consider getting other headphones.