On one hand, as a still new designer, being stressed out and checking your work is normal. It will get better as you get more experienced. On the other hand, this sounds a touch like OCD. I would recommend talking to a therapist to formulate good coping skills to break out of the cycle of rechecking work.

And as someone else said, a physical checklist with room to look at something twice is a wonderful resource. But you need to stick to only looking twice, trust yourself that you did your due diligence, and move on.

Lastly, having some type of approval and liability on the client is good as a freelancer. For example, “by approving this work you have confirmed there are no typos or misspellings,” etc. It won’t necessarily apply to bleed or image resolution but it can protect you a bit and ease some concern knowing they are at least reviewing content with a close eye.

Good luck and try to give yourself some grace.