Ughhhh I cant decide if I want to try ferber method on my 5.5 month old

She wakes up 5-7 times at least every night. She drinks milk at least 2 times out of those times. I work full time and my husband works over night so getting up is up to me alone, I'm super exhausted. I have tried all the sleep sacks, the putting down drowsy but awake method, the patting back with paci as well and nothing is working. She was teething a month ago and also went through Regression couple weeks before that as well but its going on 3 months of no sleep

I would like to try this method but not sure if its the right thing, I feel bad letting her cry even just for a few minutes.