You're eating almost way to clean for what you stated your goals are. You said you have trouble eating 1700 calories, but i think that is cause the food you are currently eating is so clean that its hard to eat that much worth. You're a smaller guy, add some white potatoes, red potatoes, steak, white rice, fuck even get some flavored rices to add a few extra calories in there. Pasta and ground beef is a favorite of mine, add some cheese and BBQ sauce and boom, thats extra calories. If you're really hitting the gym 6x a week 3 of those crossfit, you're def burning through the food you're eating.
Championship powerlifter Chad Aichs pointed out in an article that an enormous salad with like 6oz of chicken, a little cheese, and some balsalmic dressing was around 300 calories. A snickers bar is 220, and 440 (obviously) if you eat two. I am not advocating you to just start pounding snickers but i hope you see my point in that story. Calories are going to be calories. You can find more calorie dense foods pretty easy.
Food is NUMBER ONE for ever and always, most anabolic shit on the planet. That being said, for someone in your case, look at the possibility of a mass gainer from a reputable company. Some of those shakes are like 600 calories a shake. Drink one right before bed and boom again you've added 600 extra calories plus extra nutrients to the day.