Aaron Carter's Ex-GF Says Family is Trying to Save Him from Himself

Aaron Carter's ex-girlfriend says he has a warped view of the world right now -- thinking his family is out to get him ... and that his toxic fans are his closest allies.

We got Lina Valentina Tuesday night outside the Dream Hotel in Hollywood, and asked if she was concerned about her ex-BF in the wake of concerns regarding Aaron's prescription medication, gun talk ... and his mental state.

She tells us she truly is, and explains exactly why. BTW, Lina and Aaron dated for about a year before splitting up a month ago -- so she has some interesting insights.

First off, Lina says Aaron's family is not the enemy here -- this, of course, after Aaron's older brother, Nick, obtained a temporary restraining order -- which got aired out all over social media, with Nick claiming Aaron threatened to kill his pregnant wife.

Aaron denied that ... and went on to say he wants nothing to do with Nick or his family. It's just the latest sign for worry in Aaron's life.

He came on "TMZ Live" over the past couple days defending his mental state, claiming he's more than stable ... and, more importantly, NOT going to surrender his firearms. He's had a couple police visits lately too -- with attempts to 5150 him, to no avail.

However, we've learned authorities are looking into a way to seize Aaron's guns for his own good through the use of an obscure California law. Unclear if it'll work.