I know what you mean, I'm a little guy too. What I'm saying is that there are ways to apply chokes that can, for the most part, negate the strength of a bigger fighter. If your opponents grabs your arm to prevent the choke then turn it into a straight armbar or an Americana.
I understand that for beginners this might not be something that's easy to do, but practice makes perfect. I learned these technique combos by f*cking them up hundreds of times, now I can, for the most part, get them right.