Pain and bras - UK advice needed

Hello my fellow UK warriors. I’m 40F, one child, chronic pain sufferer since getting covid (technically my diagnosis is long covid but my symptoms fit fibromyalgia far better than any other chronic illness) and I’m getting deeply frustrated by this particular question and would appreciate any advice.

I have big boobs - 36/J as per a measurement at Bravissimo this past week - and I cannot find a bra that fits, feels comfortable, supports me and doesn’t trigger my pain. I thought I’d found one and bought it, but I’ve been wearing it for the past hour and my shoulder is killing me.

I wish I could go braless but I can’t. They’re too big, they droop, they are mismatched in size so I look lopsided if they aren’t in a proper bra, and I look scruffy and unprofessional. I have got to find a bra that fits me, but any time I think I’ve found one, I end up with shoulder pain, back pain, chest/breast pain, irritated skin, or a combination of the above. The only thing I’m comfortable in are bralettes or comfort tops with minimal structure, but they really don’t make them for my size, and I look very lopsided.

Has anyone got any ideas where I can find a bra that lifts (a little, at least!), supports and above all keeps me comfortable? I am getting desperate.

Thanks in advance!