Here's what I have now:
When ex-high school hockey star Elliot Wexler finds homeless girl Lucy Pembroke in his dad’s shed, he isn’t sure if he should call the cops or invite her in for hot chocolate. ( HAHA! I like how he considers to invite her in for hot-chocolate! )Eighteen-year-old Elliot spent his entire life preparing for the NHL, but after a blowout with his team and a failed suicide attempt, he quit playing and was diagnosed with bipolar disorder. ( IDK why you jumped to Lucy. Is this told in two POVs) For seventeen-year-old Lucy, survival is everything, even when she owns nothing more than a backpack and a heart-shaped box. Despite their differences, Elliot falls for Lucy, so when his family lets him stay home while they go on vacation—knowing that his mental health needs stability—Elliot invites her to stay with him.With Lucy around, Elliot feels like he can get past the ostracization he faces at school, maybe even play hockey again. But then she disappears. Searching for Lucy’s true identity, Elliot discovers three things: Lucy’s parents are dead, her abusive ex-boyfriend might be behind it, and she’s classified as missing. But Lucy filled the hole in Elliot’s heart, so he doesn’t want to let her go, even when her ex-boyfriend stands in the way, even when every time he finds her, she leaves again ( This reads awkward. I wonder if you could introduce her always leaving and then the ex-boyfriend) . As Elliot tries to keep Lucy with him, his mental health declines—until it comes down to either getting help for the girl he loves, or getting help for himself.
So your query is getting better with every revision!! That's amazing. Also, I was kind of sad you removed Elliots attempt to suicide from the ended But it's okay... The stakes are still good. I would work on a few things as noted above... Other than that, you're getting close to a ready query