I appreciate your honesty, I can relate b/c I've been there at points in my life too, including the weed. three things helped me kick/reduce all those habits:

1. stop expecting perfection from myself by giving myself lots of internal validation every day & replacing self-loathing thoughts with gratitude
2. break apart overwhelming tasks into stupidly small tasks like "write the first word of the first paragraph, then the next word, etc"
3. be my own parent & stop using weed, other substances and addictions like videogames to distract from the present by deciding to take short breaks (e.g. 1 day/1 week/1 month) & telling myself I'll keep going if I feel good after

I can recommend a book called Don't Believe Everything You Think, it's a short & easy read that reminds you why it's good to be in the present & that all the answers you need are already within you if you're honest enough with yourself to ask & answer those questions. good luck!