Just be honest bud.  I mean 6'5 280?  350?  I am not asking - none of my damn business and frankly don't care  - just saying be specific with prospective providers.  I have been nicknamed "slim" more than once so I can't commiserate, but Lord knows I have my own sexual idiosyncricies and I always communicate my needs honestly, openly and in advance to assure a good match.  This will also serve to alleviate a lot of stress for you in advance of the date, knowing she is on board and OK with things

"I has money?"

Kidding. Most professional ladies will see you and show you a good time as long as you are clean and polite. It's not a bad idea to describe yourself in your first contact just in case they do have a problem with seeing a big guy. BTW, you don't say how big; there are plenty of guys in this hobby who are overweight, unless you are so big that some positions are hard to achieve, it shouldn't be a problem.

All kidding aside, this is not about how old you are, how much you weigh, or how you look. It is about how you TREAT the providers you contact, that you show up clean, and always be a gent. I don't mean kiss her ass ha ha, but we are not into the guys who are short in emails saying things like, "Hey baby R U available 2 nite?" References or some kind of screening are usually required by reputable providers who don't take chances, but there are many ways to get through verification that is comfortable for both parties.

Welcome to TER, and have fun!!

We are in the line of business that personality means far more. We don't care if you are skinny or fat, just respect and good hygiene. All about having a good time and if you can do that and let your personality show, nothing else matters.  
Check reviews and go from there. Most gals won't see young men and welcome your type immensely.  

Once you pick a gal, sit back and enjoy.

Dude you're describing me..except I'm shorter (in height!)

Most ladies are very "forgiving" when it come's to our appearance. Women in general are not as much focused on "looks" as men. As long as you have great hygiene and act as a proper gentleman you should not have any problem with the ladies. I do admit that I personally feel a little uncomfortable when I see  pretty young providers half my age - but they are usually good at easing my concerns about my looks, performance, etc.

I think you just need to find a well-reviewed lady and communicate with her honestly about your concerns.  My guess is your age and size are far more significant to you than they will be to a truly good provider, but you'll probably find yourself much more comfortable and able to relax if you've discussed your worries in advance.

I think you'll be fine, just look for a quality, experienced girl

I've never turned away a client for being overweight and/or older. Do girls actually do this? I see a lot of middle age guys because they have the means to afford my fee. I'm usually not attracted to the client but any provider worth her salt will make you feel relaxed and comfortable.  

Maybe go for one in her twenties with some experience as a opposed to an 18 yo on her first week? The later might be more immature and nervous, which could make the situation more awkward and cause you to feel insecure.  

Frankly, the young, handsome clients are few and far in between. Any girl who is expecting all of her patrons to look like Richard Gere is in for a rude awakening.  

Good luck! Keep treating us ladies like ladies

Just let her know upfront and see if she is accepting!

I luv chubby hubbys...lol

good luck!