Q.My Plants Seem To Be Having A Hard Time This Season. I Think I May Have A Soil Problem.
Some plant leaves are turning yellow. Others the plant leaves feel like they are hardening and sound like paper when I brush against them.

Certified GKH Gardening Expert
Your soil appears to be heavy clay. This can suffocate roots if not amended properly. Here are some articles that will help:
https://www.gardeningknowhow.com/special/organic/the-importance-of-soil-for-an-organic-garden.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/improving-garden-soil.htm