Oh wow, I posted and then was out until late-ish. Thanks so much for the quality replies.
I guess a huge part for me was admitting to myself that whilst I love my parents unconditionally, something was not right. Thinking back today I'd say 99% stemmed from my mother - yet my father could have dealt with things privately or in front of me. I've tucked these feelings away for so long and it becomes emotionally draining to a point where damage begins to occur. I've been in super denial about it, but now I've admitted things weren't right I can hopefully begin to heal.
My mother had a period of severe mental illness when I was young, I remember the curtain slashing, throwing things, swearing profusely around 6-7 then her being institutionalised when I was around 11 - I remember they allowed her home one Christmas Eve and she had to be taken back on Christmas Day as she couldn't cope - one of the reasons I find Christmas hard, this will likely out me but my birthday in Dec 26th too, so was very hard to take.
From age 14-15 she was at home but with outpatient appointments and the comments started. I've tried to talk to her about it but it's like talking to a brick wall.
I became severely disabled with M.E. five years ago, leaving me bedbound and with shit mobility - every joint and muscle in my body is permanently on fire and I have to use a wheelchair. Periods of insane stress can manifest like this - another reason I need to heal.
Teaching was my calling, after being told I could not study, I self taught myself into a very narrow niche in IT (web coding when nobody knew what the web was - and functioned myself a good career as a result, until my DP became severely ill during pregnancy, yet I never received any praise). Actually, regardless of what I did, praise was never forthcoming.
I have self-referred to two therapy services - we don't need to go through the GP initially - so will see what they say. I will pick Toxic Parents up and read with interest.
Humbly, from a guy perspective, thank you for the empathy. I'm equally sure many of you have had problems with admitting something was wrong initially and this thread has helped educate and open my eyes. I will definitely head over to stately homes.