I relate. I have a hard time understanding what I am feeling, or if I am feeling. My heart rate is the best tool I have at my disposal to know if I am feeling something or not. From there, I might think about the situation at hand and then insert the most fitting and appropriate emotion word to express what I may have been feeling. But was I really feeling that? I dunno. The only emotions I seem to know from the get go for me are amused, pissed off, and calm. Maybe I should add confused to the mix though...
I'm not so great at knowing what others are feeling... mostly. If I look at a person who is just sitting there, unless I have known the person for a long time I would not know if they were bored, tired, sad, content, whatever. They would have to be screaming before I guessed angry or crying before I guessed sad. Or some kind of extreme expression.
I do better at guessing the emotions of people I have known for a long time though as they seem to have repeating emotion/situation patterns I can recognize. Also if I am very familiar with someone, I'll get to know their 'angry face', for example. Most of the time people have tells, it seems.
Not sure if that is what you mean, but I do understand not being good at knowing ones own feelings.
_________________
"...don't ask me why it's just the nature of my groove..."