I am angry to think I have paid all this time for someone else's retirement.I thought the money I put in was for me to collect later!
This is what many (most?) people think, but if you read up on the system, it was never designed to be that way. It is not an investment or pension plan in a traditional sense, but has always been about transferring money from current working people to retirees (or the disabled) who no longer have significant income, so that those who need it aren't subject to abject poverty.
The amount of benefit is somewhat related to the amount of earnings that you had throughout your life, but it's never been the case that there is a specific amount set aside for you.