which would be better for me wing chun , kyokushin karate or muay thai?

Style is irrelevant. What counts is finding a good instructor. Muay Thai is a ring sport. As such, many of the grappling, locking, and more dangerous techniques were removed. I never recommend a ring sport for self defense. Kyukoshin is also taught within a heavy sport context, however many schools also put emphasis on self defense. Wing Chun was designed for self defense. I reviewed the schools. The last one was Aikido not kyukoshin. However, Muay Thai is not designed for self defense, it was modified for the ring. Aikido is an excellent martial art if taught right. As is Wing Chun and Kyukoshin. Go to the schools and forget the styles. Whichever has the better instructor is where you should go.

Probably wing chun which was designed for a smaller person as kyokushin is very physically demanding with punishing practice, as is muay thai.

One might ask why you are studying Aikido if you do not believe in its effectiveness and or not benefiting from it?

namaste

Kyokushin will make you tough

Listen to Man of Faith he knows of what he speaks!