First of all, buy a crib tent! If he can climb out, then you need a crib tent! And while some moms have great luck with toddler beds at this age, I think most 18 month olds are still too young. (My guy would just get out of the bed constantly.) And a toddler who can climb out of his crib can also fall out of his crib! :(
Have you tried a night light in his room? This age is rough, because they're so much more aware of everything than they used to be. My son is going through a similar issue, but it's whenever we go to my parents' house. They have a great bedroom set up for him, crib and all. And he's always slept great there! But now, he cries and screams and gets so scared. So I take him to my bed and lay with him quietly, just gently soothing him. Then when he's getting very, very sleepy (but not completely out!) I gently take him into his crib. He still cries, but he stops after a few minutes. The same thing happens when he wakes in the night (which is also brand new). I soothe him in bed, and then take him back to his crib.
It's ok to soothe him gently now. He just needs to feel safe and comforted, after such a scary storm. Once he gets back into sleeping through the night, you can go back to sleep training.
He'll figure it out- just follow your gut!