I purchased a new home and have been trying to sell my old home 2 years. I have tried renting it, but the renters don't pay and I have had to spend money in court evicting them. It is getting to the point where it will be difficult for me to pay for both houses. Should I just let the house foreclose? How will that affect my credit? I have heard it stays on my credit report for 7 years. Can the bank come after me in any way for the money they lose? Or will they just take the house?

They would take the house and sell it and come after you for the difference
Like if you still owed 27, and they sold it for 21, they would want the 6,
PLUS any costs they might want to charge you with.