Is US dollar becoming worthless?

Today, I had an embarrass moment. After eating lunch, I took a walk to CVS and bought a bottle of Pepsi. I came to the register to pay. The clerk scanned the bottle, I took out $2 and gave him. After awhile waiting to get my change back, I asked "Is something wrong? Is the cash register stuck?" (I was serious and sincere). He replied "It's $2.04, you're 4 cents short". I didn't have any more $1 bill so I had to use my check card. What an embarrass moment! I overvalued the dollar and thought $2 would be enough for a bottle of soft drink. Since when is it $2? When I was in college (which isn't decades ago), I can buy the same thing at the same place for $1 / $1.25. Now after 2,3 years it's double? Is it inflation or the dollar doesn't worth shit anymore? If they keep printing out money out of thin air in Washington DC to pay debt, next year a bottle of Pepsi will cost $3. The next thing is US dollar will lose its place as the world's reserve money. 8,10 years ago if you graduate and making $50,000 / year that's a lot of money, now you gotta be making $100,000 to be able buy the same stuff you did 8,10 years ago. It makes no sense. I want my paycheck deposited in my bank in gold, please.