You haven't crossed that line yet, but you are VERY CLOSE TO A RELAPSE.
Alls I can say is: get yourself to a meeting, or if you can afford it, an addiction counselor. Like, now. If theres a meeting tonight GO. If not go tomororw. More importantly though, when you get there SHARE HOW YOURE FEELING! Tell everyone you want to use! Dont hide it otherwise you will have no support or help in dealing with it. Tell EVERYONE and ANYONE who knows/cares about you you are that close. If the people at your meeting are worth half their weight in garbage they will help you!
TALK AT THE MEETING! You MUST share, otherwise its just a place to go meet addicts and listen to others. Listening does help, a lot, but you need to SHARE THESE FEELINGS NOW! Idc how afraid you are to talk at the meeting, you talk your fucking ass off, and by the end you will have a few people offering to help I can guarantee.
You need to share these feelings bro with someone face to face. I can only imagine how much its killing you holding in how badly you want to use. Its nothing to be ashamed of when around other addicts: they've all been there and then some.
I dont go to NA regularly anymore but this is honestly the best advice I feel you can get: GET OUTSIDE HELP! It doesn't matter from who/where, just do it, and NOW before that plan to use becomes a reality/