It's not too late! I started at 19 - just a few years before where you're at now, and it worked out for me. As long as you have the interest to light the fire underneath you, I truly don't think age matters. Now, life comes with priorities, and maybe you will have to deal with filtering art into your existing schedule (assuming you're actively pursuing medicine?) That's totally fine. Learning anything - but especially art- takes time, and I think so long as you can devote even 20 minutes to drawing and painting most days, you will make progress. With art, it's the tortoise that wins the race: slow and steady. 22 is still very young (I'm almost 40 over here); imagine where you could be by the time you hit 30 if you devote 30 mins to your development every day! Practice your drawing fundamentals first. Be able to envision the 2D page as a 3D space. Linear perspective allows you to do that. Be able to work with or without a perspective grid. Be able to design 3D forms (simple forms, boxes, spheres, cylinders) on the page without even trying. Draw lots of gestures to understand the mechanics of motion and weight. Combine that with 3D form, to be able to build quick gestural foundations which you build upon to make physical objects. Then add light into the equation - using a single light source to illuminate parts of the form that face the light, and everything else is in shadow. All the while be aware that you're drawing on a 2D surface, so the 2D shapes you make are always of critical importance. This is a brief overview of the fundamental path I took to become professional. I hope it helps, and all the best with your journey!