How can I understand my feelings about someone I have only known for less than a year?

What a great question.  Feelings and relationships can be so complicated.  It is important to really have clear communication in the beginning stages of dating.  Communicating your feelings, expectations, wants, and needs to your partner is vital.  Along with this clear communication, it is also important to respect how your partner may feel.  You can't always assume that your partner feels the same.  Asking questions, and expressing how you feel can help you not only to understand the feelings you are having, but also get a clear understanding of how your partner may be feeling.   Keep clear communication so that you are not moving forward with a false interpretation of how the dating/relationship is going.  

Also if you find yourself moving very fast or have strong feelings in a short amount of time, check in with yourself. Lust and passion can feel a lot like love.  The feelings of lust and passion can be quite intense and give you false expectations of the relationship.  Try to understand that early in relationships, lust is what gives you a strong sexual attraction.  Lust can also make you feel that you have a deeper attraction to your partner than you actually do.  

Love on the other hand comes with time and patience.  Keep in your mind that to love someone you must first get to know them and that usually takes quite awhile. When you're feeling love, this feeling is usually created by a host of different interactions, conversations, and generally getting to know the person on a deeper level (which takes time).  Love involves understanding a person fully, building trust, vulnerability, and acceptance.  All the things that create love build over time.  Although there is no real time line to when love can be achieved these points are good indicators that you're moving in the right direction.   Remember moving too fast can sometimes intimidate your partner and cause potential issues in the future.  In addition to creating potential issues in the future, moving fast can bring discomfort and sometimes guilt to your partner.  Moving fast in general seems to create the discomfort you mentioned above.  If you feel that you do this often, try to remember these points, ask yourself what's the rush?  

Take out the time to really process and understand your feelings so your can differentiate the feelings of love and lust.  Hope this help you.