I just failed 😩😭😩😩

I just failed st my first attempt at sleep training. My son is 2 months old and my Dr told me he should be sleeping 6-7 hours consecutively during the night time. He is a really bad sleeper. As a newborn he was up every hour. Right now he's up every 2 hours through the night and from 4am stays up until about 6. I am beyond exhausted. I am essentially a Zombie. I make sure he gets 4.5 ounces. Pamper is dry and that he's comfy but he still always wakes. 😩😩😩. She told me to put him in his crib and walk away. Let him cry for 5 minutes then go check in on him for a very short visit. Increasing the amount of time between each check in. I couldn't last 3 minutes. He screamed his head off and he has an umbilical hernia so I'm scared to let him cry. Help!!! I'm so tired. What did you mamas do to sleep train?