Help put my sick dog to rest

My Bailey is 13 years old. Hes been the most amazing dog, my best friend.  He has had a big tumor growing from his belly which is hard and just gets bigger. He has a bad ear infection. His legs shake. His head is tilted to the side. Hes in so much pain, he limps and can barely get up the steps. I do not work or have any income and my family has alot of financial issues also so this is my last resort. Im please asking for some help to put him to sleep peacefully asap. Anything will help, thank you so much in advance.