214A>22B is a good basic combo ender. 236A is sketchy. If I'm scared of combo proration I'll do 214A>22A.
Your pressure is just a bit weak. Rachel has no real reversals, so get right in there. Charge a bit, and run right in so that you can get a 5a. Reset your pressure. Both in block strings and in the middle of a combo. If you get a crouching combo on Rachel, sometimes you should just reset pressure after 6b. Run back in after 2b sometimes. Try some jab pressure. etc.
If you do an ender in the corner, with the opponent in the air, you want to use CCB if possible. Charge the 22B as much as possible so that you get extra charge time or the option to 6C>236236C.