@darkangel1720,
Being thought of as mentor is a great feeling. Teaching and molding a young, inexperienced mind is always something to strive for. Having said that, having that young person not learn from the advice given or subsequently, argue their position as an equal and not a subordinate would make that relationship uncomfortable.
When you come in on your days off or stay after your shift, you became a distraction to the manager on duty. Not only does the manager have to watch the business and supervise the working employees, she now has to babysit you and watch that you don't get hurt on company time, and not do any work that you don't get paid for.
When you sat down during a meeting adjacent to your manager and district manager, you failed to take in account they could be talking about how to re-evaluate the staff, cutting hours, increasing hours, who to fire or who to promote. All that information is supposed to be confidential.
You need to learn to maintain a healthy business relationship versus a personal relationship. You can ask a mentor how to calculate a employee FTE model to further your knowledge in staffing hours for the business. But you ask a personal friend for advice about something other than work or to go to the movies with you.
In other words, you treated you mentor as a friend, not as a respected person whose experience and knowledge who you value. Next time, make sure you know where your place is in the chain of command. (Hint: not management)