Magick hurts me ?

Usually feeling fatigue during or after a spell (for me) means that it isn't going to work out well in my favor.

Always have enough energy. Grounding is great for this. Mother Earth will give you some. Appreciation would be to give back what you didn't need. This way you don't drain your own. After magick, rest and try to eat. Drink water. You'll be fine. BB...

Meditate before doing spells, also ground and crown, protect the area you are working in. Do not let outside influences distract you. It is that simple, if this does not work, it may be worth consulting a doctor.

After spells are done try eating an apple and giving thanks and offering to Mother Earth this always fixes me rite up after over exerting myself

I find headaches happen too. I've really been looking into broadening my horizons in Magick arts and lately I'm finding myself sick and fatigued more frequently, as well as splitting and all-day migranes....

Is there any alternative to apples? I am asking because I am allergic to apples.

I don't have that problem, I'm just interested.

Try eating and drinking before casting. Could be part of the problem.

As for headaches or other ailments, try opening your body in that area. I personally do the Middle Pillar and it clears up my headaches, colds, etc. by the time I finish. Maybe incorporate that into your practice at the end for a few times to see if it works.

Thats b. S. Aeson and oakgrove. Meditating helps you focus more, increasing the probability that the spell will manifest. If you do not ground and center correctly you will feel ill because the magick is using your energy and not the energy from another source channelled through you that can sustain the spell. You both are confusing the two. Look it up.

Do you cast too often and too many spells?