The greatest gift you can give right now is give him a little space to feel comfortable with you and try to work on these insecurities. All the money in the world may bring a person happiness... but it won't make them happy around YOU necessarily. The only way he can be happy around you, is if he is comfortable. That means no more freaking out... and putting forth effort to work on YOU so will be able to offer him the best of you.
Think long and hard about why you feel so insecure around him. Write all of these reasons down. Then think about all the reasons you shouldn't (or don't have to) feel insecure around him, and write those down too. Then, write all ways that your insecurities could hurt your relationship. And last, write all the ways fixing your insecurities can help your relationship. This will give you a chance to review over your thought process --- figure out what's really going on.
Example:
Why I feel Insecure
Because I have been hurt in the past
Why I Shouldn't Feel Insecure
Because he isn't the same as the guy that hurt me in the past
How These Insecurities Could Hurt My Relationship
He may start to think I don't trust him
How Fixing These Insecurities Could Help My Relationship
He will feel that I do trust him, and can be comfortable around me
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen