2004 Vauxhall Astra ABS

I there I have a problem with my brakes
i have no abs warning light showin but my brakes fell heavy and dont work any where near as good as when I bought the car I have to press the pedal down hard to stop as pressing it the way u are ment to only slows it down but its not enough as then u have to press the pedal hard again this is a real concern as I have a young child thats always in the car is there anything that u can suggest as a couple of people think it can be the abs sensor or the whole pump
would be gratful if u can try and help me out
cheers