Am I doing this exercise thing right?

sarahahum

I finally found a form of cardio that doesn't make me feel like death and that I really enjoy -- the exercise bike!

Here are the details:
I am 5'2" and about 200 lbs. I usually do 30 minutes at a tension of 2 (on a 1-8 scale) at around 17-18 mph. I work up a sweat, and get a post-workout high, but don't really feel like I worked that hard after the fact.

Basically, am I doing this right? Is that enough exercise and strenuous enough to help me lose weight and get in shape? Do I need to increase the time or the tension to make it more effective or is this good for now?