Sleep regression at 13 months? Looking for advice

Hello parents! I have a 13-month-old baby who has been waking up every night at least 3 times. Today, he woke up 7 times before 6 a.m.

Each time, I go into his room and find him sitting in his crib, whining. I help him lie back down, and he falls asleep immediately.

I’m really exhausted and can’t keep going like this. I’m not comfortable with letting him cry it out.

Two weeks ago, he was sleeping much better, only waking once or twice during the night.

I’m writing here to ask for advice, if you’ve experienced something similar, what did you do to improve your baby’s sleep?