Can I just add herbs into lotion?!

Technically, you can... but then you've got chunks of an herb that won't make the lotion feel very comfortable (especially if said chunks dry on your skin with the lotion). It's not the most comfortable thing in the world, nor is it very fun to pick those chunks out of your lotion as you apply it... kind of like putting on sunscreen or lotion on the beach and picking off sand that sticks on.

You'd be better off to just buy an Essential Oil and mix a couple drops into your lotion than to boil the Chamomile into the lotion as you'll get the smell of the Chamomile in there (which is the main relaxing part for most people). Good luck and I hope I helped!

Personal experience and personal research in my role as a Product Specialist for a vitamin company (we carry lotions and whatnot)