My origin randomly just closes. and when it does i cant join games obviously, and yeah... anyway to fix this shit??

Does it give you some sort of error? Is it reproducible? The easiest way to try and fix it would be to run the origin self-checker thing. Next would be a re-install. If that doesn't work out, check that your firewall is allowing it to work publicly.

some notice pops up when it starts but it comes up with mediacom redirecting it or some bs so i cant read it. whats the origin self checker?

If you're running win7 make sure you're running it as administrator, that tends to fix a lot of these weird things.