Going Through Separation, questions

Married 8 years, 1 child 6 year old son.
Co-own home, $207k value $158 left on mortgage. 30 year lease.
Wife owns business which I helped to finance and build, devoted countless unpaid hours to managing finances, etc.
Wife wants separation. Claims emotional abuse.
She doesn't want divorce because of expense and because she wants to keep home and business.
I left my job of $70k per year to work for her. Still pay cs to 1st child based on that salary, have never modified.
Current wife wants me to get a job and move out.
Wants to split custody 50/50.
I want to work on marriage, don't want to move out, want to keep family intact. She doesn't want counseling, "nothing more to give."
I've already been through separation once before, and I know it's not all roses.
Not to mention expense, business is still highly leveraged, etc. etc.
Am cut out of business as of now, other than answering her questions as they come up. She's angry, resentful.
We're cohabiting, I've been leaving house at night to give her space. Trying to keep things on shallow end of pool. Her animosity to me however is palpable.
Actively looking for a job, but market is tough.
Credit is not good due to her business (late payments, etc.) so not sure about my prospects re: apartment.
Don't want to move out until we have a legal, notarized Separation Agreement that at least spells out who will be responsible for mortgage payments, debt payments, child care, etc., until a divorce can be finalized later on when we are more financially stable.
She doesn't want to sign one.
Open to suggestions on how I approach this.