ANSWER:

What you are doing is sinful and innovation! There is no need to keep spitting your saliva as it does not break your fast even if you swallow it.

I have chronic sinus issues and some mucus from my nose might be dripping down to my throat. Now, this is something I cannot ever control. What I do is I try to blow my nose and spit as much as can throughout the day to minimize the chance of mucus going into my stomach. Given that I cannot really control this much and I am doing my best , are my fasts valid? Thank you!