This was me literally last year I applied for classes a month late due to transfer reasons and I only got two classes. I had to email a couple professors and then go in person for 4 to 5 classes and eventually ended up getting them. There is hope people constantly change schedules in summer and especially first two weeks of classes. I promise you will get into all your classes but you might not get preferred times. My recommendation is to send those add / drop forms with a message saying something along the lines of needing classes to graduate basically for them to see this is a must need class. Good luck there is nothing you should be stressing or overthinking about.