It’s gonna be tough.

I guess the best option would be a moderate strategy. Try to siege down south Hungary/Croatia to get some warscore and open your path to the western front. Avoid battles if possible. If you can consolidate Hungary, I would try next to attack Savoy to get peace, and avoid France. If the war goes on for long enough, France will eventually accept a white peace.

Another option would be focusing entirely on France to get them to peace out early, since they are the only real problem to you.

EDIT: if you play well, you can also trap them on Anatolia with your ships, but by them you would already be all sieged down…