All I have between me and them is a flimsy sliding window that constantly falls off its track. It doesn't latch when it's shut and the door unlock button into my office is right inside the window - very easy for someone to either jump through the window or reach in and unlock the door to let themselves into our office.
I tried to explain to my boss that I felt unsafe about the window and door lock/lack of lock situation, especially after a schizophrenic woman reached through and grabbed my shoulder as she told me someone was trying to kill her and he was following her and might be right behind her. But his response was "we are working on a safety plan for the whole building. The front office is not priority right now. I expressed again that I felt unsafe and would really like to at least change that window so it locked and maybe put some film on it that makes it more difficult to break, but he dismissed me and implied that he would write me up for insubordinance if I pursued getting quotes on my own.
My only recourse was to buy several cans of pepper spray with dye and keep one in my pocket all the time, the other hanging within easy reach under my desk and a small stun gun. I know nothing about how to diffuse hostile situations, how to talk these people down when they come in and are angry because we won't give them gas cards, cash or bus passes (most of them come at 4:30pm on a Friday when literally any social service group is closed - they always wait until the last minute then get REALLY {inappropriate language} they can't get what they want. Reeking of cigarettes or weed but claiming if I don't give them something, they'll starve

I did do my concealed handgun license training last week and will submit my in person application the day after Christmas (the first day I have off of work that they're open). I have a completely clean background and have had my BCI and FBI files checked many times for different jobs in secured areas. I've never committed any crime, never been arrested, don't have any social media, have had one speeding ticket in 96 - in 36 years of driving. But of course, I can't bring my weapon into my job, so I'll have to leave it in the car (which is parked right outside of my office with my eyes on it all day). I'm frequently left completely alone in my office and occasionally alone in the entire building with lots of entrances, hidey-holes, stairwells, dark areas, etc.
Any suggestions anyone has for me to protect myself within the constraints of my job would be very appreciated. I'm especially looking for ways to learn how to de-escalate crazy/drugged up people, some subtle 'tells' that they're going to become violent, what to do if they pull a gun or knife on me, how to alert my coworkers that I need help and that they are also in danger (they think I'm being silly), when I should just run and where I should go (a friend who is a homicide detective told me not to run outside because I'd be outside with the bad guy - but how will I get my weapon if I don't?). If there was an instance where I feared for my life and the lives of others, am I allowed to then bring my firearm into the gun free zone?
Sorry for the length, this has been bothering me a lot and was the catalyst that encouraged me to take my CHL last week. I just want to feel safe.