How difficult would it be to get a TS

I am a veteran of 14 years in the military. I previously held a TS in the military (more than 12 years ago) that was revoked because of an investigation, then reinstated after investigation was complete. During that time, I had married my husband, who was enlisted in a different post from me, and I was warrant at the time. Needless to say, my command didn’t like that and gave me a letter of reprimand and article 15. I wanted to be with my husband and just asked to get out. The command found a way to get me out with a honorable discharge, but an unacceptable narrative. At the time, I didn’t care, but as I go forth seeking further jobs under DoD, I am wondering if that is hindering my chances of a TS clearance. I currently hold a secret clearance working for a DoD contractor.

Anything that happened over 10 years ago is mitigated by time. As long as you are completely forthright in answering the questions on the SF-86 there should be nothing to worry about.

Even if they gave me an unacceptable conduct on my narrative in my DD214 and a separation code of BNC (Misconduct, moral or professional dereliction or in interests of national security?

Yes, for every three years since the event he issue is downgraded one level, it would not be an issue.