No Cgst input and high sgst input

For last two years we were getting IGST Output but no IGST input. So, IGST output was paid from CGST input. This has led to a situation. Now we have no Cgst input but have high sgst input. To pay Cgst liability we have to pay via cash challan. This has choked the cash flow in our business. What is the way to come out from this problem?