No you’re not going crazy, it’s OCD. OCD makes us question everything about ourselves. This happens to me, you’re not alone.
Yes I dealt exactly with that! Sadly no amount of checking will ever satisfy OCD. The best thing you can do is ignore the thoughts. Try going 5 minutes without checking, then 10 minutes, then 30, etc. This will build up your tolerance of uncertainty. I know it’s hard, I’ve been there. Try starting off small and be kind to yourself!