You can do it if you have a strong will power. Your self control and will-power will make you that strong to take a stand. Else you will feel alone and you will not be able to help yourself, you will find yourself helpless and no one will be there to help you out. Think about the things again as you might find some way to solve out the problems and you get the man you love. And if you already have checked and finally decided that you just have to leave that man, do not wait for a single minute and start cutting off gradually. You can not do it at once, just do it gradually and make that man too to live without you. Do not leave him desperate and alone as this is not fair in love.
Another idea can work if you talk to that man about all of your problems and then see what he says. But talk to him if you find him an understanding and thoughtful companion else you might have to face very awkward situation. It is also possible that he says you want to get rid of me now and other stuff like that.
So, this is just your own will-power and self-control that can make you strong and consistent to handle the situation as you want to.
Another idea can work if you talk to that man about all of your problems and then see what he says. But talk to him if you find him an understanding and thoughtful companion else you might have to face very awkward situation. It is also possible that he says you want to get rid of me now and other stuff like that.
So, this is just your own will-power and self-control that can make you strong and consistent to handle the situation as you want to.