Can atenelol cause negative thoughts like fear or health anxiety?

Yes: It's not a common side effect, but it is reported. Also - anxiety seems to be so prevalent these days - and especially for people facing medical concerns - that it may have arisen on its own. Consider some CBT therapy to learn how to manage it. With your other physical issues, I'd try to avoid a medication addition unless absolutely necessary. Take care - get well.

Maybe: The only thing that i can tell you is that it can cause depression. Talk with you doctor

Atenolol Side effect: Per Drugs.Com, side effects may include: "Discouragement, feeling sad or empty, irritability, lack of appetite, loss of interest or pleasure, trouble concentrating trouble sleeping, anxiety".