It's self-deception to believe that your issues with self-esteem and insecurity are made to be better or worse by your partner dating or not dating other people. Those issues are there regardless. IMO, "taking breaks" is about whether the insecure person gets to ignore their insecurity or not.
If you've got a lot of other emotional issues you're working through, I think it's valid to ask for time to work through them before adding more emotional stuff to deal with. But, if life and your emotional state are good apart from this one issue, there will never be a better time to deal with it.