Can I sue for age discrimination?

(Location: Florida)

if the post is too long, I'm rlly sorry!! i'm trying to respect the rules of the subreddit and explain my situation in as few words as i can, while providing all the details.

As you may know, the Florida Civil Rights Act of 1992 defends against ALL discrimination, regardless of age, race, gender identity etc, so I (19M) am legally protected from age discrimination even though I am under 40. I have been working at a golf course for 2 years now. Earlier this year, they hired a new Director of Golf, which, based on my position, makes him my manager. He has completely transformed the previously stress-free workplace into a hostile work environment. I mean like he's disrespectful to everyone, loves to dictate and delegate, super misogynistic... seriously, anything else you could think of most likely applies. For over a year now, I have been working 35 to 40 hours a week consistently, I have never been reprimanded for anything, and I've gone above and beyond with my only goal in mind being full time status. It is the only thing I want, as I plan to become financially independent in the near future.

About a month after he took the position, I asked him if he could get me full time status, because my previous managers kept telling me to "keep working hard and keep my head up!" while making no effort to actually help me. He said absolutely, and it shouldn't be an issue at all. Around the end of March, he shook my hand and told me that I was now full time status, in the coming days I received an email saying my status has changed, along with the benefits info I was required to fill out. About two weeks pass, and my supervisor calls me into his office and tells me "Manager asked me to tell you that they can no longer offer you full time, it's a budget issue, sorry kid. However, they are willing to offer you a 1/hour raise." I said "I guess, if its my only option, I'll take it". My supervisor has been my mentor in a way, so we trust each other. Later that day, he described the conversation that they had. My manager had told him "well, if he becomes full time, I can't hire a second assistant" with is excuse being "He's 18, why would he need benefits!". Now, I get it if the budget is tight and he NEEDS the extra hands (he absolutely does not, he is more than adequately staffed, delegates his own work to others, and leaves work multiple times a day out of boredom), but the way he mentioned my age as a reason, when I am more than qualified, just doesn't feel right, or more importantly, legal.

from what I understand, age must be the number one factor to succeed in court, but "cutting costs" seems like an easily deflatable argument on the company's behalf, because of the following:

1. If it truly was a budget related issue, they would've reviewed the costs and immediately denied my request when I asked, instead of randomly revoking my status two weeks later. Clearly it seems like a decision that HE made, not from the general manager or HR, considering they had zero knowledge of it until my supervisor told them.

2. A few weeks prior, the manager promoted my coworker, who has the same position as me, to be his assistant, receiving a significantly higher salary.

3. if the company does, in fact, have a budgeting issue, then he has genuinely done such a horrible job at cutting costs, for example, selling already discounted shop inventory at up to 60% off every month since he started, to the point where nobody will purchase anything until there is a sale. He has way too many employees on the clock at once, and has been hiring more employees for his station, while my supervisor and I cover all the missing shifts in our station due to improper staff allocation.

Last month (July), my supervisor went to tell HR about the way my manager has been acting, during which, he described my situation to them. I feel the need to clarify, HR has never taken any action about any problem for any employee at my place of work, ever. They send an email to someone else because the issue is either "not their job" or they just type it into Microsoft Word and click "don't save" when we leave. Now months later, as you may have guessed, nothing happens. I am so sick of being of no value to the company I've been loyal to since I entered the workforce. I know that tends to be how this country is, but I just wont accept this outcome. I have submitted my case to a highly rated civil rights attorney and I have begun searching for a new job. My supervisor has agreed to testify in court and I am sure my family will be very willing to confirm the emotional distress that this situation has caused me.

Do I have a proper legal case with my own testimony and supervisor's firsthand witness as evidence, or am I totally screwed?