Used 30x30 Marlin I'm A Short Skinny Guy - Where Do I Find Clothes That Fit?

I'm a short skinny guy - where do I find clothes that fit? - used 30x30 marlin

For example, my pants 29x29, but smaller sizes are 30X30 Standard (29x34 or obese people for short).

Even if I cut one 30X30, still feels very loose, as it is designed to resize.

I even thought to go, the children's department, but it seems that the different styles, and I'm not even sure what should be the size of because they seem to use a different numbering.