How to get my sinus to drain? My nose feel fine but doctor said throat is red and ear infections. Sinus won't drain. Nose feel fine. Cheek pain.

ENT doc. See the sinus specialist - ENT doc, for evaluation/recommendations.
Decongestion. Sinuses drain when you decongest the drainage pathways. Simple interventions include decongestants like pseudoephedrine taken orally. Prescription remedies would include nasal steroid sprays. Additional adjuncts include nasal saline irrigations and mucolytic such as guaifenesin. If you can get sinus pathways to drain better, you are less likely to develop a bacterial infection and you'll have better symptom relief.
Decongestants. I often have my patients try Mucinex (guaifenesin) D (mucinex (guaifenesin) loosens the phlegm and (D =sudafed which decongests the nose)). One can also try a Nasacourt nasal spray (it is now over the counter). Finally a saline Sinus Rinse can help as well.
Why? If there is no infection in sinus you may want to get your throat and ear infection treated instead and not to worry about sinus drainage.
Neti pot. A neti pot is an effective way to moisturize and flush out sinuses with saline.