Firstly I think it's brilliant that you want to get out there and try a club or naughty night, if everyone did more of it the world would be a much more chilled and sexy place! ;-)
I've been to a few places and parties and suchlike and the one thing that has struck me is that despite what you may think, nobody is perfect! ;-) It is a likeminded people of all sizes, creeds and the rest being themselves and generally having a good time.
Of course different places have different themes etc but one thing that is common to all the places Ive been to is that they are non judgemental will not tolerate people being viewed, judged, whatever by their size or body shape.
In my first ventures I was the opposite to you and as a guy I judged myself to be too skinny and may be not fit in with all the perfect bodies there (I too thought that until I got out there! ;-) ) How wrong could I be??? The people there, like in life outside were a vast mixture of all walks of like and every body shape imaginable and I found it brilliant that everyone could get along so well and just enjoy themselves in whatever kink, fetish or sexual preference they had.
I'm on the fetishistic side of things and been to places as a guy and as my TV alter ego and thoroughly enjoyed both sides, indeed it was through this scene that I discovered that I adored BBW's and loved their company .
I was very nervous the first time but once I'd got changed into my leathers and started to mix all inhibitions and doubts were soon things of the past, and remember everyone has a first time and everyone feels the same on that first time.
I'd give you the same advice I'd give to anyone with self doubt about their bodies or looks who is thinking about going to a club. Get in there, look around at all the different people there and then realise you had nothing to worry about!! ;-)
I'm in the North West so cant really advise on the Midlands, but I really do hope you find somewhere to suit you. Good luck and have fun! xx