[Problem with my old zafira]

Hi, I am having problems with my 2002 zafira club 1.8 petrol

When I start it up its revving ok, then goes down to almost stalling, does that for 5-10 minutes

Then when I'm driving it's kangarooing, and lurching forward and back 

Also losing power on hills right now, but if I try taking my foot off the accelerator and back on a couple of times the power returns

 

Any ideas?