I'm Going To Smoke Crack Until I'm Dead

LET ME SEE HIM

Bam Margera is having a meltdown because he hasn't seen his son in over two months ... threatening to smoke crack until he's dead, unless he gets to see his kid.

The former "Jackass" star just posted an alarming rant on his newest social media account, ripping his family and his estranged wife, Nikki.

Bam says Nikki and his relatives are driving him to drink ... and he says waking up every day knowing he's probably not going to be able to speak to his son, Phoenix, makes things even worse.

At the end of the video, Bam threatens to go down to the boardwalk to smoke crack with the bums until he's dead or until Nikki allows him to see his son.

Remember ... Bam's desperate to have a…