STYLETHREAD -- LET'S TALK SHOP!

I've been using Mozilla Firefox and Thunderbird for a long time now. I got my current laptop a year and a half ago and installed them both then. Since that time, Firefox has been awesome but Thunderbird is getting worse and worse. Even when I have the program open, it goes through these phases, which can last five minutes or two hours, where I can't do anything. I can read my emails, but they stay bold (as if unread) even after I look at them. I can't delete anything, get new mail, or send mail. Basically I can just read emails. It's so frustrating! It used to just be for a few short periods a day, but now it's like this far more than it is actually working correctly. So I'll open my email and every minute or two go in and check and see if I can do anything yet, and when I do I start emailing/deleting like crazy because I know in a few minutes it will suddenly stop working again.

Has anyone else had this problem? Is there any way to fix it? It's especially frustrating because I use this email for work and sometimes I can't get or send important emails efficiently. I'm teriffied of trying to fix it and instead screwing everything up, so I was planning on waiting until I went home to visit my family again and have my brother help me. But if anyone else had this problem and had an easy way to fix it, please help! I don't know if I can wait to see him, I'm going bonkers!