(What I am going to ask sounds harsh but comes from my seeing parents spending their entire retirement/emotional savings bailing their kids out of substance created financial/legal trouble again and again and again.)
If you are going to ask your parents to bail you out of the is situation financially make sure you are actually going to be honest with them. Please do a inventory of your motivations. Do you really want to quit and improve your life or are you doing this just for a financial bailout so you can keep smoking it up?
I say this because I care and do not what to see this cycle start with any other family. Please make sure this is the last time.