I lose all my text messages and phone numbers

This is probably because it is running out of memory. Blackberries will automaticall delete your SMS/Emails Logs when it has run out of memory.

Check by going to Settings/options --> Status --> File Free Memory.

It is very low, then you will have to hard reset the device to clear the cache. By pulling out the battery while the device is on, leave it out for 30 seconds and put back in. This should increase the memory. Otherwise delete some apps of the device or clear out emails/sms to make space.