Hodlhodl or bsiq exchange will be good to sell Bitcoin anonymously, you can also use ithis exchanges to buy Bitcoin without no kyc.
In addition to this: bisq has limits on how much you can trade for fist but I don't think it has them for stsnlevoins (could be wrong though.
When picking a stablecoin, please do your research to determine which is best as done are shadier than others (for example I'd personally stay away from tether/usdt).