I honestly do not think you look bad, but you could look better in my honest opinion. I think your friends are telling you the truth. However, I noticed you do not look quite as healthy as you could be. You don't have to be a body builder or a model, but a little more slim could do you some good, and even then you are healthier to boot. It's a win win situation. Even more then looks, I believe honest good people would on average like to be with someone who looks after themselves and takes responsibility of their lives, rather then the opposite.
If you do plan on losing weight though or changing your appearance, please do it for yourself at the core. Changing just to get a girlfriend is a big nono, because the chances of finding a girl based on someo0ne you are not increase every time you make a chance in your life or about yourself that you aren't primarily doing for yourself. You may even attract the wrong kind of girls this way, and that can be very bad. I wouldn't want that to happen to you.
I hope my post helped! Remember to always be yourself when you change, it's very, very important! ♥