Some sort of discharge coming out of cheeks and gums?

hi So I've had my braces for about a year and a half now and they've been quite problematic. The most recent issue which I suspect is also a result of the braces, is some type of weird discharge that comes out of my cheeks and gums. My other guess is that it might be thrush but thats just from things I've seen online and the internet isn't always reliable. I've tried to bring it up at my orthodontist visits but im really really shy and he intimidates me so that hasn't exactly worked and I always think that if theres something wrong then he would notice. Anyways texture ways the discharge(for lack of a better work) isn't fluid but more like little crumbs that gather into larger clumps. Its not painful but theres a little bit of soreness in the cheeks and I can feel the pressure of whatever that stuff is within my gums. It also mostly only comes out when I bite. Like chewing gum isn't possible because of all these clumps. I've never had this before getting braces and since having them its occurred once then went away after I had my wisdom teeth removed and this is the second time. I'd just be grateful for any ideas because it's really annoying and bothersome. Thanks