One big, warm, tight, hug, handshake and howdy, moose-sized official type welcome to the site.
This place is amazing!
What's your son's name? My oldest, Gabriel (6), is seeing a therapist each week so Little Man and Daddy Moose can sort out what's going on. He doesn't have many 'highs' but a lot of lows and crying.
From what you've said, I think you're doing everything right so far. The worse thing we can do is ignore the issue. And keep in mind...
You are not alone.
You are one of us.
And we are here to help.