How would you feel if you no longer had this job?

For almost three years now, I have worked at the biggest and craziest supermarket where I live.
I worked as a courtesy clerk-bagging groceries, refilling the check-stands with bags, getting other supplies for the cashiers, doing service outs, helping customers shop that were injured, blind or handicapped, doing price-checks, getting carts, doing clean-ups and doing perishable go-backs.
Out of everybody who worked my position, I was made by the cashiers and front-end managers to do the most.
Courtesy clerks that were lazy or mentally handicapped would be able to get away with not doing much and disappearing.
I could never go through a shift without hearing my name called a lot.
I didn’t always mind hearing my name because I was liked by coworkers.
Coworkers that called on me but didn’t like me recognized that I was a hard-worker and reliable.
I had no benefits to this job despite belonging to a union and paying my monthly dues.
I usually just had 16 hours a week until two months ago when I a little more than 20 hours a week.
Management did not want to promote me.
There were courtesy clerks that did less than me or I helped out get promoted over me.
I had assistant managers talk down to me especially one who blackmailed me.
Some of the assistant managers even made me do stock when it’s not part of my position and a union violation.
I was recently suspended and then fired.
Nearly three full weeks ago at work, I saw a coworker who I had not seen for a week because that coworker was on vacation.
I said a comment to her jokingly which made her laugh, I then asked her about her vacation and then went back to work.
My store manager called me into the main office that night and asked me what happened.
He said some customers complained about me and were worried about my frame of mind.
I told him exactly what happened and then he told me that I would be suspended and that Human Resources would have to “investigate me”.
The comment I made to my coworker had nothing to do with race, religion, sexual orientation, physical or mental disability.
I just used the “F” word.
The comment I made to my coworker was not a threat to harm anybody, myself or to destroy the place I work at.
I’ve never even assaulted anyone at this job.
I’ve never sexually harassed at this job nor have I ever called in “sick” or simply not shown up for work when scheduled nor have I ever stolen anything from this job.
The letter from Human Resources was dated on November 22nd (two weeks ago) and my last paycheck was included.
I contacted my Union representative and he could not help me out.
One of my coworkers found it funny that I got suspended.
What he did was worse than me.
Once, he told a customer,”F U.”
He wasn’t reported by any customer to the store manager.
I’ve thought about going back to this job at least one more time to get some coworkers phone numbers to use as personal job references.
I only have a few of my coworkers numbers so far.
This is the only job that I have been suspended and fired at.
I’m more depressed right now than angry about losing my job even though I knew the longer I stayed there that it was dead-end for me.