The latest AMD CPUs seem to overclock rather well with stock cooling, until you start to overvolt. Once you crank up the Vcore, the stock CPU generally can't take the added thermal load.
As with any overclock, the best steps are to isolate various parts of the system and stress test them individually. This means using a large memory divider while finding the CPU max, a 1:1 memory ratio or a multiplier when finding the memory max, and a large memory divider and a low multiplier when finding the motherboard max.
Keep your HTT around 1000 (right now you are at 200x5 = 1000).