{{{HUGS}}} to you!
Quick question for you...has Roan always been around the same percentile in weight? If so, it's okay for him to be long and lean. That's how my DS has always been, and it's just the way he's built. DH and I are both the same way, so genetics plays a big part. Tyler looks much thinner than he is because he's so tall, but he's healthy and growing. Just something to think about and hopefully give you a bit of perspective.
As for your eating struggles, take a deep breath and relax! :)How many ounces of breastmilk/formula is he taking per day? Those are much richer in calories than most solid foods. Keep in mind that lots of babies start getting finicky about how and what they eat around Roan's age. My DS ate NOTHING but finger foods from 9-12 mo and screamed every time he even saw a spoon. So if Roan would prefer to eat finger foods, that's okay. There are lots of healthy options out there. And of course, just when you think you have it figured out, he'll probably decide he'd rather eat from a spoon today, thank you very much. ::)When that happens, just take a deep breath and roll with it. And you're absolutely right...you can't force him to eat. If he isn't hungry, that's fine. Take him down from the high chair immediately, before either of you start crying, and try again later. Remember that healthy kids don't starve themselves, and repeat that to yourself over and over. Some days they seem to survive on air, other days they'll eat you if the food runs out!
You can get more bang for your buck by only offering healthy foods, especially ones that are high in fat like egg yolk (can be mashed into just about anything), avocado chunks, whole grains, whole fat yogurt, cheese, and peanut butter when he gets a little older. Please don't be so hard on yourself...you've got a gorgeous little boy and you're doing a GREAT job!!!!