its suddenly goin really slow, apps keep force closing or don't work at all and then it freezes. It's gone like this all of a sudden

Most likely a memory problem.

Reboot the phone and see does the problem persist.

Most common issue on android is when you open the app most people don't bother using any built in close button on the app and hit the home button. This leaves the app running in the background and using vital CPU time and RAM, hence a slow down.

Rebooting the phone will forcibly close all the apps as one solution.

Another is to manually go into the task manager and close them.

2 more preferred solutions though:

1) install GoLauncher Ex, its a homescreen replacement that on my 2.1 device looks alot better than stock and seemed more responsive. Not only that but when you open the app tray there is a button along the top for running apps, hit it and it has a "close all" button which will close any running apps. You can also set up a list of apps which cannot be killed, I recommend adding any email client to that, if you use a VPN app then add that aswell and then the same for any data monitoring app like 3G watchdog and antivirus apps. It will close all your hungry apps like angry birds and fruit ninja that have been stealing your system in the background too though.

2) install any other app killers (used to be one called "droidkill" I believe, not sure whats out there now). They should function the same as GoLaunchers one, its just GoLauncher makes it more easily accessible.

Thanks for that. I'll try that and see what happens

You could also try the App 'Fast Reboot'.

Tried the re boot and Nothin. Half my pictures in my gallery are just blank grey with a exclamation mark on them?

In that case I suspect you may have some sort of memory corruption although you would have normally had a bunch of error messages. I'd advise either seeking out the android support forums (many experienced people there although with very little patience for anyone with android knowledge below theirs for some reason) or the store you purchased the phone from. Carphone warehouse in the UK are also very helpful when they aren't too busy.