my parents were like you when i was younger (i'm 33 now), and i was much like your son. the greatest gift you can give your son is 1. time, and 2. a safe space. when i would lock up in the car for what seemed like an eternity and my mom looked back in the rearview, i never felt threatened by it. i knew 100% that i could lock up for a full minute and she'd be waiting for me to respond, just as calm and welcoming. when your son knows this, that psychological safety is, in turn, a tool. stuttering is overcome or exacerbated moment-by-moment by the type of response he receives from others. of course, continued therapy would always be helpful, but you may find like i did that the best gift you can give him is comfort. that alone can momentarily cure a stuttering episode. you're a good parent. of course you want to move mountains or give him all the tools in the world, but you can't physically help him in a given moment- you know that; even more, he knows that. i'm sure as a family you've already come a long way with just acceptance and seeing the stutter as a part of him just like a leg or ear or eye. consistent comfort and trust. that's what moved mountains for me. another perspective about this stuff, too ... at least for me ... it made me feel worse when i saw my mom trying to physically help when i knew she couldn't. it made me feel so helpless that i had a mom that was trying her damndest, and i wasn't making progress - because it doesn't work that way. i suppose a loose analogy would be like if you were laying flat just over a 30 foot cliff with your arms fully extended, prepared to pull your son up from below .... if he's only able to jump high enough to latch onto your arms. but, he can't just 30 feet. no matter how much you are prepared to catch him, he just can't be perfect. now imagine you're him, looking at the impossibility of leaping 30ft in the air, knowing that you're putting in blood, sweat and tears to be there -- and he'll always be letting you down. so, taking the foot off the gas, acceptance, comfort, and the deep and unceasing support that i'm sure he knows you're always willing to give - these things go a long way. feel free to reach out on private message. i've helped many parents with what you're going through.