Please help, I think my hairline suggests that I am going to be bald! (photo)

No, this is a very early maturing process that your hairline is undergoing. Most of your juvenile hairline is still present. If your hairline fully matures, it will take on a V-Shape. The hair you lost is just the corners which will eventually go up along with the center hairline.  It is just the part of getting older and wiser.