This happens to me all the time as well.
You just have to keep spending time in the Electric Moment of Truth, and the stiff arm are the best ways.
Also when they push back into you use it to your advantage, go stoner control and sweep them back the other way and then make them pay with a vaporizer, upper belts hate this! Also you can use that deep half position to sweep them back on their butt. I have done that before in competition. Since they are literally on top of you they won't always base out and you just wind up sweeping them the opposite way and getting on top.
There is always the 50 game, but I suck at that.
Those are just a few ideas. The other thing I could recommend, and something I have been spending a lot of time with lately is getting more proficient at dog fight. Lockdown half needs to be able to go two ways, to the electric chair, or up to the dog fight. The more you go to dog fight and attack from there with half and halfs, and old schools, they will have to respect that game, and then when you drive in for the fake they will push back into you harder, and bam, you hit the electric chair.
Also someone showed me this video last year of a black belt, who I don't think is affiliated with 10p, of attacking a knee bar from bottom lockdown. Check it out:
https://www.youtube.com/watch?v=jkhX...NbJDMql_p0Cnb8