Being highly emotional is a very common condition. It is sometimes caused by mood swings and depression. You might be suffering from depressive illness, which is a condition that is often misdiagnosed but also very treatable.
2 Additional Answers
Some people are just more sensitive than others. It doesn't mean there is anything wrong with you. In fact, many men and women seek an emotional partner.
There are many reasons that you could be very emotional right now. You may be going through some personal issues, or it also maybe that you have unbalanced hormones. There could be many explanations for emotional behavior.