If you feel like you feel emotions at more intensity than others, usually it's just that you're more reactive than others. People can have low emotional stress tolerance.
If you are often told you overreact or feel like your mind is coming apart, splitting, or like you're not yourself (or feel this way looking back at past extreme behavior), and you have a past of trauma and emotional abuse/neglect, and often think in extremes/black and white, you might have symptoms of Borderline Personality Disorder.
Borderline Personality Disorder often has feelings of 'splitting' or different versions of yourself/identities coming out when you're emotionally overwhelmed or in mental distress.
No this isn't a diagnosis. Just that you have symptoms. But I don't know your life situation and personality, and stress level. These symptoms can also be signs of other disorders, or things as simple as too much stress, low frustration tolerance, poor sleep habits, and drug use. And having borderline type emotional states (going from one extreme to another quickly) also serves as symptoms of other possibilities.
If you want you can get it checked out, but I always say do that as a last resort personally. Try other solutions like setting a sleep schedule or looking into emotional grounding techniques, and how to recognize distorted thinking.