It's good to see you are motivated to be a good Dad. I think the disability payments will also help you purchase medication.
In my life, antidepressents helped ease depression the most, but suppliments are also helping.
I experience avolition, a symptom similar to depression, and it's similar to amotivation syndrome too.
So be careful about smoking marijuana - on Wikipedia it says that heavy use of marijuana is linked to amotivational syndrome, and that's definitely something you want to avoid, if you can.