my boiler is in need of help, as am i!?

please help, my boiler is reading 3.5 bar upwards when it is off, it is leaking a fair bit at the back, the thing hasnt worked for almost a year but this morning started to leak and yesterday was when the pressure rocketed from below 1bar when we tried to refill it using the loop, it rested at 1.3ish but when we closed of the water shot up to 3bar, we have tried to bleed a radiator (the only one we can get to at the moment) but nothing happened to the pressure, please not im only 19, i have no experence with boilers i only know certain things from desperate searching on the internet please help! it is a biasi boiler and im guessing a combi