Help HELP!! Galaxy S errors!!

[poundy78]

For some reason my galaxy s has decided to just come up with a load of errors..
When i turn it off then on, a small box appears in the centre of the screen with null null and CK underneath. To go any further you have to click on the CK.
I then get a box saying Sorry application Twlauncher processcom.sec.android.apptwlauncher has stopped unexpectedly. Force close. Then i click ok and i get the vertical box again null null Ck.
I click it again and it goes.
If i then try to get into my home screen it goes black with a loading icon then a box appears the same as before twlauncher.
I can receive phone calls but nothing else.
If i try to send a text i get Sorry messaging process com. Android.mms has stopped etc etc...
Sorry to waffle but i have no idea what to do?? I cant get to settings i dont have that many applications downloaded. Is there a reset button on the phone? But will i loose my pictures??
Oh it all started to go belly up the other day when i started to get pop ups saying low on space database storage is getting low.
It told me to empty my call log, texts which i did but still the same message.
If anyone can help i would be sooooooo grateful.
Cheers
Matt

 

[beer-in-box]

Try to enter the recovery mode(By turning the phone and holding the Volume Down + Home + Power buttons for a while) and do a factory reset in this menu. This will delete your apps, your settings. But won't delete your files.