It is ok to like yourself. Really, you have my permission. Without devolving into a diatribe, let's just summarize with mainstream media and various industries make more money if you hate yourself. Add a female gender to the mix, and you've got a wonderful barrel of monkeys of image issues. Listen to the little voice in your head that says, "Damn, I look good." (It's even quieter than the one pointing out the not so fine points of your physical being). Don't worry that you'll come off as arrogant because what you are really developing is confidence, and there is a difference. As a friend once put it, confidence is "I'm pretty good." Arrogance is, "I'm better than everyone else." So don't worry about your self-esteem being too strong until it crosses that line.
Sex counts as exercise! Unfortunately, you aren't likely to find it listed on myfitnesspal, sparkpeople, or Fitocracy. Even masturbation burns calories. Obviously I haven't found any scientific studies to give a more definite idea of the math involved, but sexual activities that result in sweat, heavy breathing, and lethargy obviously counts as physical exercise. If you're wanting numbers to plug into your calorie counter, then use your best judgment.