Welcome Xela! You have come to the right place for support
I have been overweight since I was a kid. It's great that you have set a weight loss goal for yourself. Setting a goal motivates you to accomplish it. First, find an exercise that you enjoy doing. Burning calories doing something you like will help you lose weight faster and you won't lose interest in it. Personally, I LOVE cycling. Since you are shy, why don't you try something like Zumba? You can do it in the privacy of your own home. I downloaded some videos off the net and got addicted. You don't feel the time pass by. There are lots of Zumba vids on YouTube. Work out to some that have songs that you like.
I know its easy for me to say this, but don't let what other people think of you discourage you from going out and having fun. I used to be so shy when I was younger and used to cry my eyes out when people used to comment about my weight. Now, I don't let them get to me. A trick I use is putting on my earphones when I walk out the door and listen to some music while I walk on the street. This way, even if someone says something nasty, I don't hear it
Don't turn up the volume too high though. That's not safe as you wont hear oncoming traffic and stuff. If someone does say something hurtful and you feel bad about it, talk to your therapist. He/she will definitely help you through it
Good luck and keep talking to us