It can just be from doing all this magic yeah, sometimes I get a headache after a lot of intense work.
He means this, it’s a servitor I created to banish, ward and protect us 
She will ward your space from unwanted entities and banish any lingering energies. But if you evoke after summoning her, she won’t banish the new energy you summoned- though she will keep you from accidently summoning parasites, or attracting them.
I don’t consider summoning anything more dangerous than summoning anything else. The important thing is to be able to banish what you summon if needed, and know how to protect yourself.
Its not dangerous at all imop. Some spirits will just laugh at you, others will take the hint to get lost.