I'm bipolar and experience the same thing. Honestly, i just try to stay conscious of my emotions and know that while mutilating her may very well keep my boyfriend from looking at her, it will both change how he looks at me and land me some prison/asylum time. Thankfully my boyfriend is very understanding of how I'm wired differently than most people, so I'm able to talk to him about these violent jealous urges without judgement, and he is now aware of how badly it makes me feel when he heavily acknowledges attractive women. Idk what your boyfriends like, but i think if you were able to discuss things like this with him it would help you too.