Am I considered fat?OK, first, you look fine to me and your weight is normal. You are NOT overweight, and you do not weigh a lot for somebody your height. You're just fine how you are!
You're already tall, so let me tell you this now (I'm tall too): you are always going to weigh more than your short friends. It can be embarrassing to weigh a lot compared to them--I was always embarrassed to weigh 150 when my short friends weighed 100 or 110. If I had to say how much I weighed, their eyebrows went up! But they were just thinking of themselves weighing as much as I did--they would have been fat at my weight. But I wasn't.
If you want to get more in shape, that's something else entirely and there are lots of good, SAFE ways to work your abs, etc. If you do that instead of dieting (which you don't need at your weight) you'll feel better, and be happier with how you look. That's how it worked for me, so don't get too hung up on that number, OK?