Consult with a local criminal defense lawyer right away and do not post any specifics here as it may be discoverable by the prosecutor. It is very difficult for someone to provide meaningful information to you about potential penalties without more information.
Retain a local criminal defense lawyer for help. Good luck.
Forgery is a Class H felony, which carries a maximum penalty of three years of initial confinement and three years of extended supervision, or a total of six years in prison. With the scant information you have provided, it is impossible to guess what your sentence might be if you are convicted. You should consult a lawyer immediately.
This answer is for informational purposes only. By answering this question, no attorney/client relationship is created. Although the legal information is accurate, it may not be appropriate for your situation. The best way to handle any legal problem is to seek the advice of an attorney.
I agree uttering a forgery is a class H felony, punishable by up to 6 years prison (3 in and 3 out). You are facing this x3 (up to 18 years in and 18 years out).
Just because you are facing 18 years in and 18 years out does not mean you will get it. An attorney would need a lot more information to give you an educated guess as to what you are really facing (i.e., you - your education, employment, criminal history, etc.; the facts of the case; the judge; the prosecutor; etc.). DO NOT, however, post any of this information online. Anything posted online may be used against you in court.
And even with all this information, the best an attorney may do is give you an educated guess. No promises and no guarantees.
Contact local, experienced criminal defense attorneys directly for specific advice. If you cannot afford a private attorney, contact the local public defender's office. If you do not qualify for public defender assistance, ask the court to appoint a low cost attorney to your case.