Coolant in oil and oil in coolant
 

I have a 97 stroker 195k miles on it. Replaced thermostat last week and drove about 50 miles got home and coolant was everywhere... Think i didnt get a good seal on the t stat. Checked the coolant looks grey deffinetly has oil in it and oil has coolant in it. No obvious leaks around outside of oil cooler. Could this be oil cooler seals issue or something worse? Let me know what you think.