It sounds as though you don't work outside the home and therefore don't have to have your son in preschool. If that is the case, I would take him out of preschool a couple of days a week and let him stay at home with you and other family members. And I would bunch the days he goes to school rather than having him on an every-other day schedule. If you were to use the alternating day schedule, you would probably still have a fracas every morning based on whether it is or isn't a school day.
In the meantime, I would visit the school and stay all morning. After observing, make an appointment with the lead teacher in his room and get more information from her. Does he usually seem happy there? Does he have friends and get along well with other children? Or do they exclude him from their play? Is he ever aggressive? The teachers in his school may echo your concerns. But it is possible that they will be amazed to hear that he resists coming to school. Believe it or not, some young children put on that act because they think their parents want them to pretend that they don't like school.
If you do this bit of sleuthing, I think you'll get to the root of the problem.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.