Nice! Definitely good to keep with the routine but like someone else mentioned, give yourself a day or so to rest every now and then.

As someone who was in the same boat as you with asthma and very skinny, I would recommend the following.

• Get a prescription for a preventative inhaler (Flovent is what I have). Really helps lessen the need for rescue inhalers which repeat exercise also contributes to. Also take a puff of the rescue inhaler right before you start the workout and you probably won’t need it.
• You mentioned “classmates” and being 20 means I’m assuming that you go to a college/university. Use the gym there as it should be part of your tuition. You may meet some workout buddies, will have access to better equipment, and just get more motivated being around others who are in shape. Don’t worry about what others are thinking of you as that part is all in your head. Everyone is there to do the same thing and focused on what they are doing, not what you are.
• Workout your shoulders. It took an injury and rehab to get me to start this, but it really helped “fill out” my frame to where others started noticing
• Keep track of progress. Take pictures along your journey to show this. (However, I wouldn’t recommend sharing with others until perhaps you have your ideal state). You’ll start to build more and more confidence as you go and continue that motivation as you can see your transformation over time.
• Know that you are young and have much more ahead of you in life. I’m almost 40 and didn’t start to really care about exercising until I hit 30. You’re starting early and I wish I would’ve done the same.

Keep at it and hope these tips from my experience help!