First of all, welcome to Android Forums, Katsu88.
Sorry to see you're having a rather serious issue with that great phone. I'm wondering if a rather common occurrence could be the cause: conflict with a newly installed (or newly configured) app/widget. Assuming your device is not rooted, and you're not struggling with a ROM incompatibility issue, it is possible that the S2 is being resource overloaded at certain moments by too many widgets trying to update for you.
Weather/social networking/email/etc.. all need to be set as best as possible to not compete for resources.
I'd start by disabling some of those, clearing cache and data on most or all of them, clearing device cache ("cache wipe" in recovery menu), etc.
Here's a short video on how to get to the Samsung Galaxy S2 recovery menu:
How to: Samsung Galaxy S2 recovery mode - YouTube
Good luck. Please post back and let us know if we're on the right track. Sometimes it can be something completely different (I'm sure others will post their experiences here
). Either way, we'll get it back to normal for you, unless it's actual physical damage (dropped, etc).