I agree with Tushar, you should be able to get usable cDNA from your RNA. I suggest that you check your cDNA by ampifying one or two transcripts from housekeeping genes. If these don't work I would not use the cDNA preparation.
Always aliquot RNA samples in RNase free vials and store at -80 C. I have used stored RNA even after 2 months without degradation. But thawed samples will lose integrity. Before using RNA, confirm the integrity by running it on gel.