The game is chase and pursuit my friend. Do not follow her. Generally, what will happen is that as somebody moves farther away, they will be chased after, causing them to retreat further away. She wants her space, give it to her. It's the best thing you can do right now.
By the way, you are handling this awesomely! Staying focused on your kids, not blowing up, etc... You really are doing great.
As far as counseling, tell her that it's not about her wants or your wants, that you two have a child together and that you two are the child's entire world. Tell her that you don't know if you will stay with her (for real), but that you two OWE it to your child to overcome your personal needs and seek counseling together. Stress to her that it will ease the break, should there be a break.
I REALLY, REALLY want you to go out to the bookstore today and pick up LOVE MUST BE TOUGH by James Dobson, it will help you out a lot at this juncture in your situation. It describes to a tee the dynamics at work at this point -- and a concrete, step-by-step game plan of how to handle things... It will also give you a positive thing to do in your off time. Please do this. I will even send you my copy if you want. There are also other books that I think would be immensely helpful, but start with this one. It helped me a lot.
Even though training is in the shitter, you are doing a great job in keeping going. Even if you totally don't feel like it, keep going! This would also be a great time to start taking about 4-6 grams/day of powdered inositol (a natural supplement). It will help with depressive tendencies without the effects of pharm meds. Split it over 3 -4 doses per day; take with grapefruit juice. Buy the powder as the caps will go too fast. You should be able to pick it up for around $30 or less for a month's supply.