I Relapsed yesterday and need advice now

Hi, I’ve been on Methadone for a bit over a week now (25mg Levomethadone) and i just relapsed yesterday and now I need some advice on how to handle talking to the Clinic Doc. So im being substituted with Levomethadone (L-Polamidon) in a Clinic in Germany (even if you’re not from Germany i’d very much appreciate your Help and Input) and i just Relapsed with F-Etonitazene. My Doctor knows that i consume Zenes and this one in particular. I don’t know if they can test for this one yet but he does do Lab tests and as i said knows about me consuming it. Either way, yesterday before i Relapsed i collected some of my Urin containing Methadone and Mirtazapine (which he prescribes me for sleeping) and put it in the fridge to keep it cold and preserved until my appointment later today (i’m not sure if i’ll get tested, it’s actually just a precaution). Anyways im now unsure if i should tell him i relapsed and that if like to up my dose to like 6 or 7 ml instead of my current 5ml or if i should keep it a secret, use my clean Urin in case id get tested and still ask for a dose increase. I’m slightly scared that he would somehow notice that the Urin isn’t fresh, even tho id obviously warm it up properly beforehands. I would either way like to get a higher dose and not fuck up my relationship with the Doc already. Please help me out, i really need some advice.

Thanks in Advance! Have a nice weekend y’all