If my husband & I arnt legally separated, but lived apart 4 all of 2017& Im go n2 b claiming my daughter who lived with me as a dependent, can I file head of household?

Yes, you can file as Head of Household even if you are still married if all of the following apply:

1. "You won't be filing jointly with your spouse; and
2. Your spouse didn't live in your home after June (temporary absences due to illness, school, vacation, business, or military service don't count); and
3. Your home was your child's, stepchild's, or foster child's main home for more than half the year (non-child dependents in your home don't qualify); and
4. You paid more than half the costs of keeping up your home during the tax year; and
5. You meet the qualifications to claim the child as your dependent, even if the other (noncustodial) parent is actually claiming the child as a dependent on their return."

https://ttlc.intuit.com/questions/2567672-can-a-married-person-claim-head-of-household-filing-status