What can this be?

Lorena • Momma to 3 beautiful babies!🤍🤍🤍
Earlier today i was in the couch with my baby and i got up to make him a bottle, when i started walking i felt pain on my foot but thought nothing of it. As the day went by the pain got worse, i got this red rash the red part feels like a ball, and my foot is getting swollen. I'm not sure what it is and im freaking out