So, hopefully you are not still dealing with Strep Throat 4 months later, but I always recommend a Neti Pot. If you incorporate it into your daily/semi daily routine, you will likely eliminate most if not all of your sinus/throat issues. Constantly washing your sinuses is a great way to eliminate the bacteria that builds up. I used to be skeptical of them, but trust me, they work. Also, gargling with salt water is a good way to kill the bacteria in the back of your throat.
Just remember this though, if you go to the doctor and are given antibiotics, a lot of times that will throw off the good bacteria cultures in your body that regulate your digestion and other things. It is a good idea, after finishing a round of antibiotics, to begin a regimen of Probiotics to reintroduce those good bacteria into your system. But make sure you get a good brand otherwise you are just swallowing your money. I use Tree of Life, Primal Defense. It was recommended to me by a nutritionist.
I know that was probably an unnecessarily long answer, but I hope it helps! Always a good idea to start thinking preventative care. Knock the problem out before it starts.