You mentioned you are interested to know how others have informed their families, so I thought I'd tell you my story.
I've been a perfectionist and have suffered from some level of anxiety for as long as I remember - even at a time I didn't realise, in hindsight I'm sure that was part of who I was. It was 2010, when I was in my mid-20s that the anxiety turned into debilitating ruminating and catastrophising, to the extent that it interfered with my ability to work and drive my car, complete my tax returns - all the adult stuff we need to do! It wasn't until 2013 when I saw a local GP, with whom I had no previous relationship, I saw them for 5 mins and they gave me a referral to a psychologist and I felt such relief at the thought I could get this sorted out! When I called to make an appointment, I was told there was a 4-month wait for this psychologist. I lost hope.
I felt I could no longer fight my battles alone. I texted my mum and said, "Can I tell you some time this week about an OCD thing?" We'd never talked about medical things before and Mum and Dad have never had mental health problems that I' m aware of, but she wrote back straight away, "Of course." She didn't ask for any details. I was taken aback at how accepting and non-judgemental nor inquiring my mum's response was. They invited me over for dinner the next night and asked me to tell them. When I started talking, I told them I was excessively worrying, I was scared to go to work, I was running over my car trips in my head out of fear of having run a red light, etc etc. the tears came almost straight away. I sensed at that time that it all clicked for them as to why I had acted in certain ways at various times in the past, in circumstances where they quite possibly had assumed that I was being purposely difficult.
Claire, as long a journey it was that lay ahead for me back in 2013 when I spoke to my parents - I've since had many setbacks but each time they are smaller in their severity now - I can't tell you the relief I felt when I shared my struggles that evening.
I think Mum has since spoken a few times to a counsellor to help her understand and perhaps also work through her frustrations, but I see that as a positive in that there is better understanding now. We have a significantly improved relationship now and they know to give me time when I need it and not judge.
I also cannot speak more highly of finding a GP who you trust to develop a long term patient relationship with.