Hello

I have bounced up and down with my weight for a while now. in 2005 I started with a Raleigh mtb that was given to me, weighed 360 at the time, and I had it modified into a up right bike. In order to do that I had the stem changed to a short steep one, and handlebars. This change moved the handlebars up by 7", and it rides like a champ. Even with the hated front fork, rock shock, I had completed my first metric in 2008 on my comfort bike.

In 2009 I was given a trek 1.2 for my birthday. The first mod to that was peddles, and seat. After 250ish miles I replaced the back wheel with a Deep V using a 105 hub. I did ride this bike at the 295-305 yo yo in 2009 for STP, and two other centuries as well as lesser mileage rides.

I can understand what you mean about looking huge. I am a short fat fellow with a 27.5" inseam, so have a 52cm frame. On the other hand on today's ride, first ride with 46cm handlebars, I did not feel so big, so I do regret waiting to change out the bars till now. I still wiegh 285 or so today. But I don't really care what people think about me on the bike. Since I realize that people will laugh at a fat person on or off the bike. At least I know that I am doing something I enjoy, provides health benefits, and lightens my mood.

So go get a bike that fits you, that is comfortable, and that you will ride. Also don't worry about what others think, that is just a barrier you create for your self.
Also remember, not all skinny people are healthy, or in good shape I just choose not to mock them for their poor life choices.