you are doing the right thing.
these next few weeks until you leave will be a nightmare. you will have a rollercoaster of emotions and he will no doubt make them worse.
why not start keeping a kind of diary as to hwo you feel, what he says and does tyo make you feel that way and the thoughts that are going through your head.
Not only will it help you release some of your pent up emotions but it will also help when you doubt your decision. sometimes when we are having a calm period in a relationship you can forget why you wanted to leave, you can use the diary to remind you why your doing this and why it is the best thing for all concerned.