How do I tell my mom about my possible addiction

I think I am on the verge of being a fentanyl addict, if I’m not already one. For the past few months I have been smoking fentanyl at least 3-5 times a week. There was a point a few weeks ago where I couldn’t afford to buy anymore and for the next few days I was super sick throwing up and having awful headaches. I was able to smoke a little bit that my friend had which made me feel better temporarily. This really scared me, so again i stopped completely smoking it and got sick with body aches, throwing up and headaches again. The only indication my mom has of me doing this was the roll of tinfoil she found in my car. I told her it was from a cookout I had went to and just kept forgetting to bring it in. I think she somewhat believed me (bc I really did have a cookout) but was still suspicious. I am really scared that I am becoming addicted to fentanyl. It isn’t to the point where I want to take more to get a better high, but I have withdrawals when I do not smoke it. How do I go about telling my mom to get help?