MacBook Pro keeps shutting down on startup after freezing checking RAM

I was in the process of checking my RAM. I also have Memory Clean installed, which tried to clean the memory because the available RAM dropped during the TechTools test. Both programs froze. I could not force quite them and had to press the power button. Now my MacBook Pro (2011) will only do a partial start up before shutting down.

I've tried clearing the NVRAM and the SMC (I think), but neither has helped. Any ideas?

Thanks.

Mac OS 10.13.5