I am an incredibly jealous person

Jealousy is poison to any healthy relationship. I understand this. I'm trying to rationalize it, to keep myself from feeling the way I feel and ruining the most lovely relationship I've yet had. She's done nothing to merit me being jealous and paranoid. I'm able to step outside of myself and realize this. I still feel the monster clawing its way out of that area just below my chest, that sinking void of a feeling. How do you deal with jealousy?

Well since I hardly feel jealousy I deal with mine through poetry or venting it out by screaming every foul word where no one can hear me or just ignore it if I know they (in your case) loves me but since I have a jaded point of view my advice is a tad twisted and I apologize

Calmly, I rarely get jealous at all but I would be calm and honest and up front with the person.

James you are right screaming "you're cheating on me aren't you!" To the person you're with won't help. Apologizing for your faults in a calm way will good luck Skyler may fate guide you