I have a problem with some irrational beliefs. I don't know how to deal with them.

For context, I am in a good school getting good grades in an employable field (CS). My worry is that I will never be able to find a job. Not that it would be hard for me to find one but that I will graduate and literally not be able to find any employment anywhere.

Similarly, when I was applying for colleges I was worried that I wouldn't get in anywhere. I had guaranteed admittance to a school but even then I was still worried.

A similar thing happens with women. It doesn't matter how many IOIs I get, I still won't think she is interested. The only exception is if she is 5/10 or below and then I am the one with no interest.

I don't have anxiety issues or other fears. Just irrational ones like these. How do I deal?