Running out of internal memory

Hey, I'm new here but have a query/problem (I have searched the forum for this particular problem but need more help).
A few weeks ago I got the low on space icon. I deleted a few apps to get rid of it, however, it came back again. I left it this time and it was about 16 or so mb. I check again, and it has decreased to around 10mb. I wondered if it was to do with apps and automatically updating themselves, so I checked and I unticked the boxes which allowed for automatic updates. However, the memory keeps going down and I have not installed any new apps for some time now. Recently, I havent been able to play music or get on the internet due to lack of space, so I again deleted some things to make room. It made about 8mb available, but I check again a few days later and its gone down to 1.4mb.
Is it something to do with text messages? I have over 20,000 messages so could it be something to do with that?
Any help would be greatly appreciated!
Thanks and sorry if I have posted this in the wrong board

Okay so I guess I'm going to have to root my phone! Thanks for your help!

I have basically the same problem... seems like everyone with a Desire has got insufficient memory issues.

Messages are taking up only 820 KB, which is hardly excessive. I've uninstalled everything I can get away with living without (though what's the use in a smartphone with no apps on it???), and moved as much of what is left as is possible onto the SD card, but still every time an app updates itself, the available memory shrinks. I now have three apps that "need" updating, but there's no space for them to do so - what a joke!

It doesn't help that it's an Orange phone so, for example, Google Maps (which cannot be uninstalled) takes up 11.89 MB, and Orange Maps (...which also cannot be uninstalled) takes up 9.62 MB. What a waste of space!

It seems to me that the Desire simply doesn't have enough memory... it's not fit for purpose. Unfortunately I'm stuck with it for another three months before my contract runs out. Not impressed. Even worse, there's still 24 GB left on the SD card; but the phone's internal storage is what counts, and there's none left. Very poor design.

Not the fault of anybody here, obviously - but still so immensely frustrating that the phone that I was assured was cutting edge when I first got it, was so crippled by simply not having enough memory. I ran out of space to install apps within just a few months, but another year later I've had to uninstall almost everything and it's still complaining about lack of space. For an expensive device, that's not good enough. I will be cautious about getting a phone from HTC again.