I also experience dull headaches on ostarine. Nothing bad really, just a minor dull ache on occasion. It always goes away on its own. I checked my bp and it was perfect so it's not a bp issue. Try drinking more water, I noticed I have to consume more liquids on osta or i get dry mouth. I would assume that's what is causing the headaches as well. Just stay hydrated!
As far as well being, there aren't really any "mood enhancing" effects because it's not a hormone. You won't feel any different mentally. You will just notice some nice lean gains in muscle and strength.