You don't need to do a full sleep study. Standard procedure these days is to prescribe an at-home sleep apnea test. A sleep health company will send you a little monitoring device by mail. You wear it while sleeping during the night. It measures your pulse, blood oxygen levels, breathing patterns, etc, and transmits your data back to the medical provider. After about a week, they send you and your doctor the results.
Then your doctor will prescribe auto-cpap therapy. Hopefully health insurance defers some of the cost, but in any case it shouldn't be ruinous for someone with an HSA. You can get a Phillips Dreamstation off Amazon for $620.
Please go get tested.