Why are my ears constantly itchy inside? And what is the yellow smelly water that comes from inside them? Doctors medication don't work.

Go back to your doc! Sounds like you have otitis externa, or inflammation/infection of ear canals. It can be caused by microtrauma from cleaning with q-tips, chronic skin conditions like atopic dermatitis, seborrheic dermatitis, psoriasis, increased keratin production, +/- bacterial or fungal infection. I don't know what med was given, but you should go back to your doctor to talk about what else can be done.
Dermatitis of skin. You probably use q-tips or clean your ears leading to irritation of your ear canal skin and production of thin unhealthy wax. You need to see an ENT doctor who will most likely prescribe a steroid lotion. Then you must leave your ears alone. Wax is protective and removing it causes problems just like yours.