Why would you even trust a therapist in the first place? If anything this "therapist" is trying to gather as much information as possible on you and whenever he senses the slightest bit of you giving up on life he would just report you and you will get involuntarily detained, i suggest you just directly cut all ties with your "therapist" because this guy is going to sabotage all your plans, that's what pro-lifers do when they grasp a suicidal person, just make his life even more miserable than it is, he won't even help you with your mental state, this "therapist" is just going to spread toxic positivity to you, he's not going to help you, he will just keep saying bullshit like "it gets better" "life is a gift" and and that bullshit, that's what pro-lifers do once they just get a grasp on a suicidal person, they will just try to sabotage their plans and ruin their lives furthermore, you should
immediately cut contact with this "therapist"
On the brighter side, you at least know where to buy SN again so it's not all dark and black, there's many suicide methods here and there's a good possibility one might be available to you already, I suggest you be extremely secretive about your plans to commit suicide, don't trust anyone with it, don't even think about telling someone that you want to commit suicide, they will just report you and you'll get involuntarily detained in a psych ward, it's not worth the risk, you at least this community where people will understand you and won't interfere against your will, you can vent here safely knowing that nobody is going to invalidate your feelings and tell you "it will eventually get better"
I understand your pain, i myself was there once when my antiemetics was taken away and trashed by my parents without my knowledge, i know how traumatizing this is, just know you have this community, you can always vent safely here