Okay, so you have actually had someone say, to your face, "I am going to do everything possible to get you fired"? Is that what you're telling me? If so, I understand where your hostility is coming from. But I have never heard someone actually SAY that to another person. I have seen it happen, ONE time, but the person doing the complaining never actually told the person they were complaining on. Oh, and btw, it backfired and got the complainer fired.
As far as employers not talking to you about your problems before firing you, again, I find this kind of hard to believe. I mean, I know there are "90 day probationary periods" in which the employers try to see if you are the right fit for the position, and I have known many people that have been terminated during such a period, but I have never known an employer to fire someone with no warning. That seems uncouth to me.
You say you "need somone to show [you] how to fix it so it [doesn't] happen again." This is not their job. Yes, you can ask where you went wrong, what you did that lead them to terminating you, but about 98% of the time you're not going to receive an answer. I have been in a managerial position before, and I know first hand that explaining, in depth, a termination can lead to such things as lawsuits, therefore most employers will leave you with a "no comment" answer rather than trying to explain their reasoning.
Listen, I'm an only child, too, and I tend to open up to people quickly, because I am starving for the attention of my peer group. However, there is a time and place for this. I have ZERO friends at work. Not a single one I would ever say "Hey, let's hang out this Saturday" or "Hey, my kids are going to be here this weekend, bring your kids over and let's have a play date." What happens in my personal life is my business, not theirs. Every girl I work with that is in my age range is trying to "get to know me better." Even the married ones. But I refuse to let any of them have even a glimpse into my personal life. They don't know if I'm dating anyone, married, single, what. I have even heard (I have extremely good hearing) "Oh, he must be gay." Sorry, but no. I'm just not interested in YOU.
As far as feeling like an outcast, it's better than letting everyone know your deepest, darkest secrets. I'm 30 years old. I feel like an outcast at work and at school. Generally speaking, I am the oldest person at both. But that doesn't mean that I am going to open up to everyone. On the contrary. Don't like working with me? Tough, we're on the same hall. Don't want to be my study partner? Oh well, I already know more about this subject than you ever will, and now you'll never get that peak inside my head. You can't care about being an outcast. You just can't. Just do your job, help when needed, but don't be everybody's buddy.
Cashier jobs generally are nothing but drama. It's another female-dominated field, and entails all that comes with that. I'm not saying that this job is better than that job, or because this job is male-dominated, there's less drama. Believe me, men can be dramatic, too. But women tend to be more out there with it. They tend to go run their mouths to everyone, complaining about this or that. It could be something as stupid as "I don't like his/her haircut," but EVERYONE except the subject of the gossip is going to know. This gossip can often times lead to things getting back to management that aren't true. Again, this comes back to finding out what's going on. You aren't going to get answers from a past employer. You can give that one up. But NEXT time you're in that situation, you know to ask up front what has been said.
You admit that you must be doing something wrong. This is the first step. Admitting you have a problem. Now you have to find out what your problem is. This is not going to be easy. But there will be some clues from your past that will give you a general direction to look in. Did your past employers say anything about use of foul language? You say you have a potty mouth. Try to curtail that. I cuss like a sailor. But I refuse to do it in front of my residents. Or my coworkers, for that matter. I may be saying "F'in this, POS that" in my head, but all that comes out of my mouth is "Yes, ma'am/sir, No ma'am/sir." Perhaps this is something I picked up from being a father. I don't like to cuss in front of my kids. They tend to repeat things at inopportune times.
Now as far as moving to an area where no one knows you, now that I know why you want to do this, it makes more sense. This is my plan when I graduate nursing school. I will likely be moving to the nearest large (500k+) metro area, seeking employment at a very large hospital. Yes, I could get hired at my local hospital or LTCs in a heartbeat when I get out of nursing school, but I want to go out and make my own reputation, not live off the reputation of those that came before me. It will be a tough move, but it is something I feel is necessary. So if you feel this is necessary, by all means, go for it. I'd say 100 miles is minimum safe distance. But also be aware that no matter where you go, you are going to come across someone that knows you. When I was 21, I moved to the state capitol. I'll be damned if I didn't end up seeing six people from my graduating class the first day I was there.