Soo tired.. Is sleep training the answer?

My husband is gone for work a week at a time, so when he's gone, it's all on me, and I have 2 other kids (age 9 & 11) I need to take care of so napping during the day is hard. Baby usually only takes 45-60 minute naps anyway. 

Long story short, I am seriously considering some form of sleep training when she turns 4 months (8/16) or even sooner if I just can't do this anymore. I've been looking at gentle methods, which I've been trying some of all along (letting baby fall asleep all by herself by putting her down sleepy but awake) and I made a little progress with that because I'm not relying on the swing or vigorous bouncing to get her to sleep anymore. I'm thinking of trying the sleep lady shuffle, and if that doesn't work, moving towards cry it out- which I said I didn't want to do, but I feel so defeated and exhausted... It's making me reconsider. I work in the medical field and what if I do something stupid that could hurt a patient? I've already had to reduce my hours, but I can't afford to quit. Something's got to give. Sorry for the long post but I needed to vent. What would you do? Have any of you had success with sleep training your LO?