u/Due-Caregiver8875

So recently i bought a 25000 puffs (def not) vape, i really don't know about the nicotine percentage because i got it from a friend, it's juice is about to end and it was %80 when i got it, i probably used like %40 of it because I usually meet up with my friends and hit it with them, sometimes i give it to them for the weekends,and it's left with %20, i started to get nervous about my health, almost all my friend say it will hurt my lungs real bad if i continue inhaling it instead of keeping it in my mouth, should I be worried ? also it's my first vape and i won't say I'm addicted, i just take 30-40 puffs at max when i want to use it, i can go weeks without it.