I've read most of your responses, honestly you do come off quite rude in some of your replies, but also some of the things you're saying make me think you're possibly autistic and chronically depressed which would honestly feel the same whether you had £1 or £1000000000 in the bank.
I think you may do well to seek a private autism assessment, and also start therapy to work through some of the feelings you seem to have. It's especially sad if you feel this way from morning to night.
I am also not rich, but I can appreciate that the life you're leading feels very different to the lives that your friends who you have grown with, and that must feel horrible.
Are there friends from work that you could do the exciting expensive things with?
Other expensive opportunities, if you want to enjoy with your friends, could they sometimes maybe contribute to those things if they were given opportunity to save? I know you would prefer to decide what you want to do then go, but when finances are a constraint of friends you either go alone, with someone else or wait.
I think you have had some good opportunities you have created for yourself, but also been really lucky to have the kind of support you do from family, that's in turn allowed you to invest your money (otherwise you'd have most likely spent money on rent,bills etc) which in itself is something that might be good to remind you is a connection you have. Presumably your family brought you up to be a confident man, who is able to make sound financial choices- was this modelled to you by your parents? I assume so. I think rebuilding connection to people stems from understanding where our connection are formed, and at their strongest, and appreciating what those connections have done for us and if its possible building on that. If there are people who have been supportive of you within your career in a similar situation maybe try and have a closer bond to them?
In 10 years time you will likely look around and realise that your connection to different people is just different.
You'll have friends you can contact to say, F1 in miami? Friends you can say, it's mum and dad's anniversary- you coming? There will be friends who are supportive in different areas, all connections but for different times.
But also, please don't fall into letting everyone know everything. You have touched on this, with saying friends think your car is financed but purchased outright etc. Never let people know you have enough that they can leach. Your money is always tied up. Whilst not rich, I have more than many of my friends, less than a few. No one knows what I do or don't have. I wave away financial conversations with "Ah! Yes! Credit card! /finance! I couldn't help it!"
Wishing you all the best.