How can I "push" my 20 year old son to get counseling on his depression without pushing him away from it and ruining our relationship?

My son recently opened up to his mom, basically stating that he's been very depressed over the last three years which stems from a bad breakup. It's affecting his relationships with his family as he's always backing out of family engagements, not spending any time with his younger siblings, etc. He's always been the type to bottle everything in, never asking for advice or even venting once in a while. He initially agreed to see a counselor with his mom but now he's wanting to back out of that as well. It kills me watching him mope around and he's starting to smoke a lot of weed, which isn't normal. I need to know there is something I can do. via /r/Parenting http://ift.tt/2hIrNFm