Pressure too high Baxi combi instant 105e?

I noticed that my boiler was making strange noises, and so when I saw the pressure had dropped to zero I then turned on the cold tap to the boiler to increase the pressure. Unfortunately it has now gone to above three, which is far too high, after bleeding several saucepans full of water out the radiators, and using the overflow pressure valve to let water escape that way, I am still finding the pressure will only drop just under three. I can’t believe I put that much water in the system? I now find when I turn the electric back on to put the boiler on, the gauge goes over three, and a pipe from the boiler starts dripping (worryingly) So currently have turned everything off.
Any ideas on how else to reduce the pressure, or do I need a plumber as recommended by the manual, (but as this was a self made fault I feel I should be able to fix it)
Thanks

Claire
September 2009