My cat is really weird?

okay. so i rescued my cat Stinky from a shelter about a year back. at the time he was about 8 months old. he was really skinny and couldn't walk straight for his life! and he always seemed off balance or dizzy (kind of like he was drunk or something) also when he ran, he would abruptly stop and skid into a wall, or sometimes just turn around and not see the wall corner he bumped into. i thought he was just a clumsy kitten, and figured he would grow out of it eventually. but he still has the same problems! and if he's alone in a room for about 10 minutes, he starts meowing in this deep voice that goes up in octave. like mraaOOW. :) i honestly have no idea why he does this, we think he might have some sort of mental retardation or neurologic problems. if anyone knows anything, please let me know!