Please I need immediate help

I need help, last January 18,2013 I signed a contract with a catholic school in calamba, then on January 23, I filed a resignation and gave them a letter stating that I am I have medical condition that needed to be attended. I had a talk with the directress and I explained everything to her, I told her that I am also hoping to find a better paying job that can help me with my expenses for my surgery, I said that it can either be teaching in public or if there's no available job in public school I will try online tutoring, she said that she is disappointed but she understand. she accepted my letter but then told me that they will accept my reason but I won't be able to teach for the whole school year in any school or they will file for the cancellation of my license. 
I can't understand why they are making it hard since according to the contract the effectivity of my employment is on May. I believe that resignation should have a 30-day notice but I am resigning with more than 90 days notice. 
Can they really file a cancellation of my license?
Can they really stop me from being employed in other schools?
Can they file any case against me?
I am really afraid because it took me almost 10 years to finish my education and have my license. 
Don 't I have the right resign?
Please help me please

Ms. Kat, I could not fathom the depth of your predicament; you must have signed a Binding Agreement with that institution that clearly states the provision of your employment, including the consequences if you put the institution on a difficult situation of finding your replacement in such short of a time. An educational institution follows a strict standard of employing teaching professionals, such as conducting a ranking, practical tests, demonstration and other concommitant procedures prior to employment proper; sad to say, they are really disappointed, notwithstanding your medical condition. You may need a real Lawyer at this particular case; this is a serious case of unprofessionalism that put the institution in the disadvantage side, and they may at their own right and previlege petition the Professional Regulations Commission's Board of Professional Teachers. The most possible scenario is that, the school will write a complaint adressed to FAITH M. BACHILLER, Chairman
with Cc: to JESUS L. NIEVES, Member and REYNALDO T. PEÑA, Member via School Liason, and a formal hearing will be scheduled pertaining to the accusations made by the Institution against your person. Teaching is a very Noble Profession, yet you will always be associated with Educational Institutions, therefore, each parties are married to each other, any breach to both parties are deemed Matters of Legal in Nature if the aggrieved party will cosider as such.

but the contract state that the effectivity of my probationary employment will start this May and I filed my resignation exactly 110 days before the effectivity of my employment, I submitted a letter and we had a talk isn't that enough to consider my resignation

It seems that you bumped into something evil; you hurt them in some way, they want to hurt you back. The entity who accepted your letter of resignation is only a facade and face with an empathical appearance; you can only contest their position over your resignation if you will get a Lawyer a.s.a.p.