In the first place what is it that is keeping you from being open with your boyfriend? sometimes if you start talking there, its amazing the feelings that will come pouring out, and you will feel alot better. If you feel vulnerable expressing your feelings, you should tell him that you feel vulnerable expressing your feelings, and then go on from there. I agree with the journal idea as well. Even if you do not express everything you are feeling to your boyfriend, just getting your feelings out on paper will sometimes spark your emotions to flow freely. You might just need a little bit of inspiration to help unblock those pathways. I find that talking after a movie which has you feeling more emotional than usual is another way to help break the ice.