Anyone here clench their teeth at night.... Did you find any store bought night guards work Ok?

It's nearly a thousand dollars to get a custom made night guard. I had one many years ago and it was 300 dollars then. I'd say nearly 15-20 years ago now. I really need a new one. My teeth have chipped and I get jaw pain a couple days a week again. It makes you feel tired , the pain. So often I have to skip a walk becasue the pain is just too bad in my jaw. It really Sucks. Anyone ever get a store bought night guard that Works? I bought one several years ago but it wouldn't even mold in hot water like the directions said. I tried many times to get it to soften so I could mold it to my mouth, but it would not soften. Any tips on a brand that might be ok in the short run welcome