You make it sound like the problem is all yours! That if you could only rid yourself of this terrible jealousy all would be fine.
Think again. From what you say, your jealousy isn't being fabricated by your own active imagination. In fact, he gives you reasons to feel jealous. That phone call incident was actually obnoxious. It's one thing for a man to be attracted to other women, it's quite another thing to rub your nose in the fact.
If you want to resolve the issue, you are going to need to involve him in the process. The next time he flirts with another woman, ask him if he likes to see you jealous. Then step back and see what he says. He'll probably smirk or laugh. Then you'll know and he'll know that you've got his number. Next, ask him if he knows what he gets out of making you jealous. Does it make him feel desired? Does it boost his ego? Is he unsure about how much you care and does he act this way to be reassured?
Get him to take responsibility for his actions. All behavior is motivated by thoughts and feelings. He needs to tell you what his thoughts and feelings inside and toward you. You could also ask him how he wants you to feel about his behavior and how he wants you to react.
Does he want you to be happy about it? Mad? Hurt? You also might consider asking him if he wants to know how you do feel about the flirting. If he says yes, then tell him. This conversation should resolve the problem because it will help him to state the feelings and needs that motivate his flirting.
For example, if his flirting is a cry for more recognition from you, then you will be in a better position to respond directly to feelings. This understanding and response on your part will make the flirting behavior unnecessary.
What's more, when he understands how much his behavior upsets you, he should want to stop acting this way simply because he loves you and wants you happy.