As someone who suffers a receding hairline since he was 19 and is now 30, shaving my head at 20 was one of the best decisions of my life. It's mostly a confidence issue, as others have already stated. Look at some bald celebrities like Dwayne Johnson, Patrick Stewart, Jason Statham and so forth... They own their look and they look good. If it's only a temporary thing for you, know that hair will grow back soon.

How to deal with it?

• Sunburn and skin cancer risk is a big issue. Always use sunblock, I personally prefer spray and gel over cream.
• Headwear is obviously important too for protecting your scalp. Whatever you prefer: caps, bandanas, different hats. Choose one that fits well on your bald head, that means a little smaller than those you used with a full head of hair.
• Exercise is, as someone else already pointed out, very important when you rock a smooth dome. Looking fit and improving your posture can do wonders for your self confidence.
• Accessories and jewelry play a very big role too for bald people. Bracelets, necklaces and big aviator sunglasses usually look great.
• Social: according to a study, fully bald people are usually perceived as taller, more aggressive and dominant than their counterparts. This isn't only positive as it means a lot of people could feel intimidated by you too. Smiling and a helpful, open-minded attitude do wonders there.

In general: if it's only for treating a medical issue and therefore temporary, don't worry too much. You're so much more than just your hair! And hair will grow back with enough patience.