Guys, back it off a bit, there's no need to be quite so rude. We all had to start from somewhere remember?
OP, let me give you a few pointers:
- As a basic starting point, the pressure you read on the side of a tyre will always be the maximum it's designed for, not what it should be run at. Running at a very high pressure means that only the very middle of the tyre will be touching the road, which leads to a big loss of grip as you've found out.
- As a rule, you'll never go far wrong if you set the tyres to the pressure as stated in the handbook or on the little sticker on the driver's door jam. This goes for regular tyres or runflats. You may find you want to adjust them to personal preference or if you are running a specific tyre (semi slicks in particular need to be run at a MUCH lower pressure), but really the OEM pressure is the one to go by.
- Runflats by their nature have a very very stiff sidewall, and looking at yours I'm guessing they're 20"? This is going to lead to an even stiffer ride than if you were running regular tyres, so it could be worthwhile considering getting them changed for regular tyres.
There's plenty more to tyres, but really that should get you right for now.