Go back, reshoot several times, bracketing with longer and longer exposures. You have multiple locations in your profile so maybe you can't go back. In that case bracket when you shoot, starting with what you think is the right exposure, then two stops more. You can make a pretty good print if you are only one stop off. Do this until you start realizing how far off you are frequently. Then shoot at that compensation in the future.
At some point you will see there is an advantage to film testing or setting your own ev.
Don't respond about film cost unless you are shooting larger than 7x17. Just think how many negatives you have thrown away with improper exposure.