Just take what you need with you, as you would for any holiday, one would hope.
Be aware that you might be fairly likely to get a small bout of dodgy tummy in Morocco. I mean mine might have been caused by accidentally eating something that I think was pigeon...
I think the Moroccan mint tea is made with a pretty generous helping of sugar.
I wasn't diabetic when I went to Morocco. They are a Muslim country, but seemed fairly relaxed about tourists wandering round not terribly conservatively dressed. Marrakesh and Fez are both pretty big cosmopolitan cities, well used to tourists. But I might just make more of an effort than usual to be discrete when injecting or be a bit choosier about which area of flesh to expose when doing it. ... Oh just checked, you're a boy, so probably don't need to worry so much about that!