The last proper clean I had was January 2020 and I can feel a buildup of plaque even though I brush so thoroughly and use mouthwash. 
I don’t think I have bad breath ... I hope not. But there’s often a horrible taste in my mouth which is only very temporarily relieved by mouthwash or toothpaste, and my teeth often feel ‘dirty’ even a couple of hours after brushing.
I think it’s just plaque buildup but any tips?