Snaked borned 1989 June 2nd

My gf is a horse born June 24th 1990. Are relationship been going good for 3 years. I'm her first love. Is there a chance she might leave me and find some else in the future. I know she is stubborn sometimes. I try to bear that and talk nicely. But what if I can't handle her. I'm afraid my bubble would burst if I hold in my anger too much. I feel like when I talk to another woman I meet. They always a feeling I think if I really want to be single or get marry. What do think I should do? Seek out and find out more about who I truely love or still with my gf that already loves me a lot but which I'm afraid she might find another partner due to her good social skills?