Why is food always stuck between my crown and tooth next to it?

I floss after every time I eat and it feels like I’m not getting it all out. Kind of like it’s still stuck in there. My gums are swollen just in that part of my mouth. When I floss there the floss smells bad and when I touch my gums and put pressure they start to bleed. I’ve had this crown for years, I’ve just noticed this food problem after I got my teeth cleaned last month. I’m thinking of buying a water flosser to help get all the food out and keep it more clean, will that help?