Yes, missing a court date can affect early release programs and other things in the criminal justice system negatively. You need to get in touch with the court where you were supposed to appear and let them know you were in jail. You should also speak to the people at the jail you are at and make sure to not miss any future court dates. Keeping on top of everything is hard for anyone to do, let alone someone in jail but you need to get yourself an attorney and get everything straight so you can get your life back on track. Attorneys can be expensive but are worth the expense to keep you from a prolonged term in jail.