@annetheagile Sorry to hear the trouble you are having with the fonts.
After the reply I received from the moderator, I decided Opera was not the browser for me. If you want to continue using Opera, the only general advice I can give you is to report a bug with as much detail as possible.
By reporting a bug, you are at least raising awareness to the developers who can test and fix it, if they choose to do so.
If you would like to provide the code for your page, I will take a look to see if I can find any errors in what you've written. Though I believe you are likely correct that the browser is not handling fixed-width fonts optimally.