I have been told my oil is leaking into my spark plugs and that my head gasket needs to be replaced
How much to repair a head gasket? on 1995 Mercedes-Benz C280
This is not a cheapie fix. Likely you also recently had the water pump fail (This likely cost around $1,000 to fix). Your head is now warped from overheating. This will likely cost around $1,000 or so to get it right. Finding someone to do the work is another issue. Your car is worth about $1,000 as far as trade in value. MIght be your best option.