HUGS to you. It is extremely difficult to know what baby needs, but hang in there and things will soon fall into place. During a naptime struggle like that, sometimes it's helpful to 1) take a deep breath and step back for a minute, then 2) bring baby out of the room and try again in 20 mins or so. After 45 mins of hysterics it would be very hard for him to settle anyway, so give both of yourselves time to calm down.
Are you using any remedies for the gas? There are drops you can give him with feedings. Also, give him some time to sit upright after feedings to aid digestion. Tracy's first book, Secrets of the BW, has a great chart to aid in disguishing different cries.
As for feedings, no, you don't always feed directly after a nap. If baby's nap was short, and you know for example he can go 3 hrs between feeds, but it's only been 2.5, just have a light A time until he is obviously hungry. Keeping consistent feed times will really help your routine fall into place. Now, I'm not suggesting to withhold a feeding just because the clock says it isn't time. But, trying to feed a baby when he's not hungry will make things tough to understand. You are NOT a loser. Being a mother is the hardest job in the world. These little guys don't come with instructions, so this is all trial and error. We're so glad you've come to the BW site for help, and we'll be here for you any time.