Vancouver guy. Cosplayer. Runner and adventurer.
Hello :) for cheaper swimwear you can look into swimming using an old binder (or light sports bra) under a rash guard (its essentially a swimming top that many surfers use and can be found in stores and perhaps second hand too!).
I’m sure you’ve already done this but keep trying to turn the knob left and see if it gets looser. Using a thin towel to give your fingers extra grip may help.
I’m afraid I can’t be of too much help because I can’t see your machine and I’m not really too knowledgable about them in the first place :( I hope things get resolved ASAP!