soft freeze? Phone clicks, but nothing can actually be DONE

Hey, I was wondering if anyone had this same problem or if it was something common among our phones for me having done something wrong on my part, like a glitch.  I read about some other glitches and bugs but none of them really matched what's happened to me.  I did use the search box and tried to find something around the neighborhood of my question too.

This is the second time it's happened.  I will be using my phone and texting or calling and then once I'm done, I will do something else and if I'm sending a text message it just does that "sending" screen and goes over and over but never sends the message and if I try to call someone then it will pull up their contact and I will press call and it says DIALING but never has a ringing or anything.  Then if I try to bring up the MENU, it will switch the 3 bottom buttons on the screen, but not show any of the items, like MESSAGING and Media Net, or "My Stuff".  And then I figured I would try and turn phone off completely and then turn it back on.  But when I hold down the on/end button, it wouldn't turn off.  I had to take the battery out, and then put the battery back in and let the phone boot back up.  Both times that it has happened, the battery was around 2 bars left.  I figured at first it may start running slow when it gets to 1-2 bars left on the battery because it doesn't have a big pool of battery life left to run applications and such, but it's like freezing, except I can select contacts and open text messages using the little envelope button on the slide out keyboard.  Also when it "freezes", the quick select button, the one that lets u choose a different application while you're already in another one will just show up as a grey box untill I cancel it out with the end button.  Just wanna see if anyone else is having this problem or if it's the battery and I should keep it fully charged as much as possible.

lol, i've been sick for about a week now, maybe my coughing and then using my phone without washing my hands has gotten it sick!  >.<