I agree with Perna, here.

Keep working on yourself, and maintaining a relationship with your children.

If she decides, that she wants to try to reestablish a relationship with you, as husband and wife, great, if not, at least you will be making effective changes that the children can respect.

I am not sure, if changes alone can fix whatever troubles over time, that led to separation. Acceptance, that sometimes resentment built over time, can prevent a person from wanting to try again, is important in the separation process.

And, if it were to lead to divorce, just realize, you are setting yourself up, by changing your lifestyle and managing your illness better, for a better future.

Is your wife, also in therapy? I am having a tough time, believing that the lack of managing your bi-polar, alone, is at the heart of the matter.