9/11 World Trade Center PTSD

I was working in the south tower on 9/11.  I don't dwell on it much but the effects of that day are still with me (18 at the time).  Almost 16 years later and the PTSD is getting worse.  I'm a strong person so I push through, but inside I feel like I'm slowly dying. Anxiety is consuming me. I just needed to get that out.  I think I need professional help.