I think, your insecurities are caused by what she did to you in the beginning of your relationship. Since she showed you that you’re not supposed to be close to other sex you would have developed the same notion. I believe that, before asking someone to abstain from something, we should be capable of abstaining ourselves. If that’s not happening, then it naturally feels unjust.
However,People change over time and it is hard to adapt to such changes and it is good that you ended the relationship. Concentrate on getting back to your old self and get busy.. Good Luck!