How did you perform the HDD test? Did you remove from the computer and check with another one? If so, that would be why the TPM error showed up (the second computer may not support TPM or have it enabled (there is also an issue of TPM ownership but that is another discussion).
More likely, either your CPU or GPU is the problem. Get a can of compressed air and blow out both the intake and exhaust ports on your laptop. May just be crud blocking airflow.