You should be able to manually install the package as Nobber suggested. It's just shell script.
Remember, the only officially recognized way to manage Slack packages is with Pat's tools pkgtool, installpkg et al, and slackpkg. Avoids a lot of headaches if you stick to them and use some caution about config file changes.
Don't be so hard on yourself. Sometimes the best way to learn is to really bork your system.
If you're having multiple problems due to improper package management, perhaps the best solution would simply be to backup your important files, hose the system, and reinstall the whole thing to get a fresh start. Extreme, but sometimes a clean start with lessons learned can be a good thing.