I don't know about PA's laws, but from what I've seen here, women seem to usually be better off in a community property state like CA unless there is egregious behavior on the part of the WAH.
Yes, it is unfortunate that your lifestyle will change in a divorce. It is always more expensive to have two households than one. If he is currently supporting you at a higher level than what you would get in a divorce, you might consider sitting on your hands until he files. But if you figure out it benefits you to file in CA, you may want to file first to ensure that.
Child support is a pretty clearcut formula, but spousal support is a bit more flexible. Do you have much in the way of assets? If you are afraid of him spinning out and not working in the future, you might choose to trade spousal support for assets like 401 ks or housing equity.
On the other hand - if his income goes up in the future, child support can be increased. If he's feeling guilty at the moment, you might want to strike while the iron is hot and get him to agree to a better settlement before his guilt dissipates (which usually happens pretty quickly).
And don't assume your lifestyle will be permanently impaired. You may learn to do more with less. You may start a successful business of your own. You may marry a millionaire for your second husband. Who knows?
I suggest you watch the movie She-Devil with Roseanne Barr. Her husband dumps her and she hilariously becomes successful while destroying him Very funny.
I make a lot less than my ex. I had to move to a less expensive part of town. My kids are older but I have been stuck helping them more than my ex. BUT - I have a successful business, professional prestige, have learned to play the drums in a punk band and have even played at SXSW in Austin with another band, I have a beautiful home, and I find it easier to manage the money I do have without my ex's impulsive spending.
If you want to go to Paris, you will go. Give up Starbuck's for a year or two and put that money in your Paris jar. Think creatively about how to save money.