You can really do anything don't let size determine, I did Tae Kwon Do (not so popular anymore) but I did it because I wanted to kick foolz in the head but for me it was speed, flexibility, endurance, and competition. I don't want to wrestle someone for 60 minutes I wanted to kick 80-90% of the time with some technique and defense but mainly offense.. Wu Shu is what I really wanted to do but it's limited where you can even find a school, I did Muay Thai as well and loved it but it was much more rigorous on my body and legs I'd have to take time off between to heal. Tae Kwon Do was fun for training and competition, I wasn't looking for knocking people out just winning. Maybe thats weak in comparison to well rounded mma but if I don't want to wrestle, grapple, dirty box, what I choose I enjoyed and worked for me. In the end a good school, instructor, program and disciplined students can make or break any martial art. Most schools will let you attend and watch a class they even may give a free week, month or a few lessons to see if you will like it because ultimately if you don't you will quit or stop going they don't want that neither do you. Maybe it takes starting at one school or martial art to find out you like another. Start somewhere you have a genuine interest get out there and try. Good luck.

Size doesn't matter.I'm too somewhat like you, skinny won't get fat etc etc and people would also say: 'damn look at your size, you'd get crushed in a jiffy'. But I took down someone that could crush me.So size is not everything.Really.

If it helps I did Taekwondo and bujinkan.I also learned some stuff from aikido,silat and systema.

You can do any art that you chose to do. My suggestion is to choose the best instructor that you beleive will help you meet your personal goals. Do not pick a style. Once you have chosen the instructor that will give you your style/art.

Brazilian Jiu-Jitsu, it is a martial art that does not require strength.