Yeah titans is heavier to run than original PA. The best you can do with that machine is increase the ram as titans really needs 12 or ideally 16gb of ram to run at its best. The only issue with that is you're gpu is about minimum for what's needed to run it well and not allot you can do to improve it when you're running a laptop...
i haven't even played a game of titans, it was actually basic PA in the titans launch. Also the menu is lagging
So you mean that the UI is slow, but the game itself performs ok? That is, pressing <Ctrl>+P in-game shows acceptable client fps?