You'd get better feedback if you showed us a mixed bag of W's and L's and not cherrypicking your wins for the video.
- you need to practice hit confirming f33, and practice your BnBs and conversions. You left a ton of damage on the table either dropping combos, using a bf3 ender without enough heat for the KB, and not hit confirming f33 or converting AA hits, etc. Without landing this damage, you're basically playing variationless Jax, as this is really the only thing that GB has over HD.
- You almost never use f2. This is one of Jax's best buttons, you can stagger it, convert off it, go into a 50/50.
- Stop using d12 outside of combos. Its such a bad string. Uncharged b2 is also a bad idea.
- Don't use bf2 cancels, bf24, or bf2 1+3 as a mixup, they're really fake, and against anyone who is decent/knows the matchup, they're suicide. Just stick with staggering f2 and its enders, 12, 121, f3, f33, f331, and grab. bf2 is ok on block, because while it has a punishable gap, it has really nice pushback that you can use to whiff punish followup pokes from your opponent.
- Take your turn with f3 or f2, not d1. You blocked a lot of pokes only to d1, and you d1'd a lot after landing your own d1.
This should be enough for now. There's a lot of matchup specific stuff. A lot of pretty ironic tea bagging going on.