One of the Starting Strength coaches suggested that I do a heavy double, then drop 10% and do AMRAP. This doesn't fix your form issues, if that's what it is, but for me, the extra volume has helped me hugely. I was stuck at 170 and getting worse rather than better at it. I also started using a belt and that has helped a lot. I pulled 190 last week and it felt easy. Soon I will do 200, yay!
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Highest squat: 167.5 x 2. Current Deadlift: 195 x 3