Why did my Husband's ex-gf blocked me from facebook? pls pls pls advise?

[Amy]

we got married 2 years ago..after 3 months of our marriage , she tried so much to break our marriage by telling me nasty things..pictures..but my husband proved that why they broke up ..she showed me all the emails where he was telling her that he don't love her and to leave him alone. Well i still kept doubting on him for LONG TIME! which created tension in our bed life..recently he told me .he wants to leave me cause i am not making him happy. Then He suggested talking to psychologist and we decided to work out this relationship..esp. i have most doubting issues. He REALLY want to work out! but doesn't want me to do stuff which made him lost interest in me. I am trying my level best to do everything he deserve. He seems to be happy in this relation now..but i just saw that his ex-gf blocked my from her profile. we were never friend btw..she just blocked me. Now, i am thinking ..if they were cheating..why would she block me? Second, maybe she doesn't want to see me and my husband pictures anymore. Our relationship is on the ROCKS! but i did ask him if he wants to go back to his gf..he said he wants me to work out with him! and never going back! cause he left her for a reason! pls give me good advise. He is being very blunt about his feelings right now..if i make more mistakes..this relation is over! and i will just die without him!
Edit - Me and his ex are NOT friends on FB.We have no contact whatsoever