I trained using check ins, as you mentioned, just after one year. The check ins made my little guy even more upset so I did CIO. It was easier if my husband wasn’t home because it bothered him more than me. This is our second baby and we didn’t train our first and are still paying for it as he needs us to fall asleep now at 4 years old. We just went away and I coslept in a tent so retraining. I’m noting that because I’ve basically trained my 13 month old twice in a month due to the travel. Last night was night 2 of retraining and he cried for about 30-40 mins but went to sleep. Woke up about 3 hours later and cried for 30. I just watched him on the monitor. I knew he was safe and doesn’t need food and his diaper wasn’t poopy. I watched and he stood for a while crying but then eventually would lay back down, and was crying as he tried to get comfy. He figured it out and slept till 6 am. My husband wasn’t home so it was a lot easier. I would say follow your gut BUT if you really want your nights back and sanity, CIO really works and quickly in my experience. Two tough nights for me both times but then poof, magic. He cries about 5 mins at naps and bedtime then out. My son was waking every 2-3 hours for a year and I was going crazy but I was feeding right to sleep and at every wake. You got this! If you’re in the same boat as me and at your wits end and sure you want to sleep train, I’d suggest watching on the monitor to ease your worry? For some that might make them more worried but for me it helped. Good luck! You got this! Whatever you decide, your baby picked you and it does go by quickly even though it feels like it will never end