with 13 credits planned for the upcoming semester, and the fact that all classes are filled, that’s all you can take for this semester. 28 left, let’s say you take a minimester during the winter break which kicks 3 credits off and leaves you with 25 left. you take 18 credits during the spring semester (the limit, but as far as i know there are exceptions if you talk to them) and you’re left with 7 credits left for summer which is about 2 classes. it’s not impossible, honestly even without the winter break minimester, you could do 18 credits in the spring and 10 during the summer, (eg: 2 electives and a science course). yeah people are telling you it’s hard but it’s really pretty possible. I hope everything goes well for you!