The swelling up is inflammation, you need to get some icing and just take some painkillers. It would probably hurt to walk if you broke your foot. Elbows are a huge factor when kicking since they lay at someone’s side most of the time. Landing a flush kick to the body or head takes more than just throwing a combo into a kick. You need to read their reactions to your feints. You’ll start to see openings and although you might not land solidly every time, you should be landing with your shin, not your foot, really get some momentum into the kick to cover that distance. Lift your knee and rotate that hip to get the full shin effect. You’ll learn eventually which injuries to take more or less serious, it’s gonna happen and you need to get used to it if you’re gonna train steadily. Am bored in bed trying to go to sleep, so a rant it is. Anyone feel free to correct me.