The only addiction I have ever had is nicotine, but it relates in some ways to your situation. [Please don't flame me, I know how this sounds but bear with me.]
I started and at the time I was 17. Me and my friend would buy a black and mild or something after school and I would be fine. But one day he got caught smoking in my truck in the parking lot and as they searched my truck for tobacco products, they found my vape with barely less than a half ounce in it.
I was kicked out, and got my second posession charge of the month. I knew my college resume was fucked, and my mild addiction became my only path to relaxation. //Note that tobacco, like hydro, is a very unsatisfying drug in itself, and the dosage to make you feel better about something like this is almost unachievable//
And like your situation, it was extremely readily available. My parents would put out their cigarettes way too early and I would half an ashy full of shorts and aces. I got pathetic. I would smoke the tip of the filter for the tobacco resin. And after all was said and done, I couldn't go a day without smoking like I had planned when my piss tests etc were done.
The psycolohical part of addiction is the worst. Every time you see some small pill shaped item, see a tylenol [TAKE a tylenol], you will be reminded of it. A pill is a terrible thing to be addicted to. In my case I would see people smoking so it is a hard thing not to be reminded of.
The only way I could kick my addiction was to start off by riding with my aggravating father from North Carolina to Texas for 2 days without a smoke and the cravings faded to the point where I could barely control it. But hydro isn't something you can ignore a couple of days and stop IMFE.
I hate to sound like my telling a success story or something, but I always saw kids trying to get a pack of cigs and was amazed that it sucked that badly to be addicted to something and here kids who didn't suffer and addiction were trying to get it, and yet I didn't correct them because they didn't ask for my opinion, obviously.
But please just don't get into it. One day your dealer will stop selling and other drugs will cross your mind. And even worse, people are always terrible about overestimating their willpower over things like this. And if you wonder how many you take to get messed up, then I guarantee you are especially one of these people, like me.
I know I can lead a horse to water, but I can't make him drink it. I hope you are wise.