Pretty much the same thing happened to me. Breaks were boring and a friend had vapes with him that had a pretty high amount of nicotine, so I tried it and it felt pretty good and made the break less boring. Did it more often as time went by until I was basically vaping on every break and I got addicted. Since I also smoke weed, I was also less opposed to smoking in general. It kinda lowers your "barrier of entry", so to say, when you're already smoking something else regularly.

I bought a refillable vape after a while tho because I felt really bad buying all these disposable vapes that create a lot of unnecessary waste and because it's a lot cheaper.

Btw for anyone who wants to switch to a refillable vape, the Vaporesso XROS 3 Mini is great, it's basically like a disposable vape that you can refill. It's small and fits in your pocket, you can switch coils by just switching the pod on the top and there's no need for buttons.