Hi SL,
Have you tried any of the Corsodyl range of stuff? I seem to be getting receding gums (have always had good strong teeth/gums). Managed to get an abscess during first lockdown, I did manage to get antibiotics but also found the Corsodyl clear gel rubbed over the general area did help, it doesn't taste very nice and it says that over time it can stain your teeth, but when in pain...! Hope it gets sorted soon for you.