How do I avoid becoming an overbearing parent myself?

My parents were pretty good in childhood.  In my adult years, they thought they were helping me by meddling in every area of my life.  I felt like I had no power.  No independence and no privacy; and it didn’t help that I couldn’t afford to move out.  There was no such thing as a secret in the family, or privacy.  My parents would feel free to comment on my sex life and my dad to yell at me like I was a naughty little girl if I ever disagreed with him on anything.  I don’t want to make the same mistakes my parents made with me, because I feel like they robbed me of what little independence or privacy I might’ve had, had they been less overbearing, which many adults can take for granted.  I’m over that now.  I’ve got a job, a boyfriend and friends.  Now my boyfriend and I have started talking about marriage and having kids; I’ve started to worry about becoming an overbearing mother myself.  How do I stop that from happening?