How come I have to eat things really slow and chew so much to swallow without choking?

Visit a doctor. There are several pathologies that can cause this problem. It could be a problem with your esophagus (food pipe), like a stricture. It could also possibly be a problem with your neck such as arthritis with bone spurs, or belly issues (ex: hiatal hernia, acid reflux). You should visit your primary care md so they can either fix the problem with meds or refer you to the right doctor.