Welcome aboard Zavi!
Don't worry Zavi, everyone has to start somewhere, and I think all of us go through exactly what you are. Also, 3 months is not a lot of time! So don't worry, you'll get there!
There is some sage advice that someone passed on to me when I was starting out. Maybe it will help you overcome the struggle.
Don't worry about the quality of your work. No matter how long you do it, your next piece will always be better than your last piece. Keep going and trying new things, and look back in a year and you'll be shocked at how far you've come.
Don't kill yourself with technical exercises. They are great to do for sure, but they can discourage you if that's all you do. Instead, make sure you take the time just to have fun, experiment, make a mess and generally throw paint around just for fun. If you don't worry about the result, but instead focus on finding ways to have fun you may find you learn a lot quicker.
Slow down. Learn to take the pressure down, both metaphorically and physically. Take the pressure down on your compressor so that you aren't moving as much paint at a time and take multiple passes to put down color, instead of trying to do it all at once. You can always add more paint, but you can't easily take away paint that you've already laid down. So thinner paint, lighter pressure, and take your time.
Finally, coloring books... one of the best things anyone ever told me was to go buy some fun kid's coloring books, pull out the sheets and practice coloring those with your airbrush. Way back when I started using an airbrush, I got a Superman coloring book, and learning to go slow and color that with my airbrush did more to help me learn than any number of classes or any other advice ever did. It also keeps you focused on fun, which is the biggest challenge any of us face.
I hope you fall in love with the airbrush like all of us did, and always feel free to share your progress, ask any questions or share your thoughts.
This is a really great group of incredibly supportive artists and craftsmen that enjoy spreading the love.