Its been 19years and i want to find my dad help?

im 21 years old last contact my mum had off him was when i was nearly 2!! i have two bueatful girls and there my world but a part off me is missin i want to find my dad and fill that hole in my heart to find out who i am!!my mum has always told me he was a lovely bloke but he cheated on her thats the last time she see him!! theres so many questions i need answeres,i just fill lost please help me how i can go a bot it all i knowis hes full name and orgin!!!