You can tell me how an incredibly bad person I am, I don't care, nothing can make me feel worse.

I am 25 and I live with my parents (I live in Mexico, so it's pretty normal, no shame pls). I have been smoking weed on/off since I was 18. I might go weeks smoking, and then take month-long breaks, and/or smoke occasionally. My parents have caught me several times during the past years. I can't recall anymore the last times, they actually think this is heroin or something like that, however I am not saying that weed is "super good", at the end of the day it kind of makes my mental issues worse (depression, anxiety, OCD and BPD) 

I know that it kills my parents to know I am smoking. When I was in university (I went to one here in my city), I didn't pay too much attention or even care, as I thought they were being very dramatic about it, and being unconsiderative on my needs ( I mean, it helps my anxiety, but I usually do more for recreational use). Every time my parents have "caught" me, I usually turn everything to them, blaming them for not trusting me, get offended when they come to my room, etc. Everything to refuse the responsability of my acts. I know that people would say that they are overracting, etc. Actually they can do that because 1. I still live with them, 2. They were financing my education (not anymore as I graduated). 

For the past 2 weeks now, I have been smoking in my bathroom at night, before going to sleep. I try to be super careful. I am not listing the "benefits" of why I am smoking lately, I think it's most of the habit and stuff. Today my parents found some small pieces of weed in my bathroom. I lied. I said I didn't recognize that, and that I haven't smoked in months. They asked me to come clean, I got offended for having doubts of what I was saying. They usually do drug-test (urine) randomly, but I use fake one, every time. Apparently they don't trust urine tests anymore, they are doing a blood one tomorrow.

I can't stop thinking about my mom. Lately, I can't stop thinking about all the people I've hurt before, starting with my co-workers (that's a long story), then my boss, my professors, my classmates, my family, and friends. But the most important, my parents. They've done so much for me and my brother that they don't deserve this. I was very immature during college, that I was so self-centered. Now I realize all the pain I've caused. And I am not talking about smoking weed, but the constant lies and manipulative acts.

It's funny how many times I say the world lie. Because that is who I am: a liar. I want to come clean tomorrow. I am not going to lie, I am planning in telling my dad that I smoked about 7-10 days ago because I was having panic attacks (which is true, and which helped me), but that is not the whole truth.

I hate myself so much for causing so much pain to my family. I feel like if I say the truth to my dad, I will place myself as the victim "aww, i was having too much anxiety, that's why i smoked" "aww, i have bpd, sorry for hurting you" "aww, i promise i wont to it again (for the 739th time)