Hi. Travel with kids can be challenging, but fun. As a former military member married to another one, I can tell you that travel can be done with kids without losing your mind, it just take a lot of preparation. I took a five hour flight at least 6 times with an infant and a toddler in tow, so don't stress, it's not too bad. Here are a few tips:
1. Make sure you bring snacks like dry cheerios, bananas, graham crackers, string cheese (most children get cranky when they're low on protein), grapes (good for thirst in this day and age when liquids are restricted) and make sure you bring an empty bottle that you can ask the flight attendant to fill with juice once you're seated.
2. Swap out your diaper bag for a backpack. Backpacks have more room and are a lot easier to carry around an airport. Fill it with diapers (as many as you can fit) lots of wipes, books, toys (an etch-a-sketch is always a winner) your snacks, paper and crayons, and baby's comfort object. Smaller pockets can hold your personal items. I would recommend foregoing the purse and incorporating your wallet and sunglasses etc into the backpack.
3. Wear slip on shoes. This is a life saver. They make you take your shoes of in the airport, and I've found that my airport experience is a lot more pleasant when I make the whole family wear flip flops or slip on sandals.
4. If you have a boppy pillow, TAKE IT WITH YOU. Your little one is likely to fall asleep on the airplane and having the boppy to rest your arms on while you're holding him will be an immense help. It's worth it to lug it around.
5. Don't skimp on the stroller. A lot of people take only an umbrella stroller to check at the gate, but I recommend taking the full stroller. You can stow all of your carry on stuff in the basket or hang it off the handle. Your son will be more comfortable and even has a place to nap if you get stuck in the airport.
6. Don't forget to take snacks for the grown ups too, and keep everyone hydrated. It helps. Trust Me.
Hope this helps and have a lot of fun on your trip.