Sewerage tank has rusted out and I don't have $$ to build one properly...?

at this time. It has caved in and now the toilett doesn't flush properly. If I take a shovel and dig it out to allow the sewerage to have some where to go, is that okay? I'd put a covering over the top... I live in a rural area. So there wouldn't be any neighbors to complain about the odor. I'm desperate.