I would not contact the OW. Personally, I do not think she needs to know one more thing about you. I would not want her to know that you still have any problems going on that you need her, of all people, to fix. Why tell her that your WS is keeping you in the dark?
Now, if OW was continuing to contact you, make herself a problem in your life, then yes, you should tell her to get lost, go away, die, whatever you need to say to her. But questioning her for info you should be getting from H, never. Do not give her the power or the knowledge that you have this divide in your relationship. She might use it to try and get him back in her life. As far as the OW is concerned, your life should be private on the inside and just peachy on the outside.
I was TT for a while and it did a lot of damage to our relationship, probably as much as the A. I feel your pain and the need to know the truth. I finally told my H it was his responsibility to keep me here, not mine. If your H wants you and your marriage, show him he has to step up. Give him firm deadlines and stick to it. Give him one week to write you a complete statement of his actions, including dates, times, acts, etc. If he says he does not know or remember, it is up to HIM to figure it out and look for cell phone sources, texts, calendars, and HIS alone. Have him document it with the cell record, copy of texts, etc. and have him sign it and date it. Give him firm repercussions you can live with if he screws this up.
Married 30+ years
2 young adult children
OW single 20 years younger
Together trying to R
Freedom's just another word for nothin' left to lose