First, I’d disable thinning; thinning only helps if you’re constrained by memory requirements, and I doubt you have a chain that’s long enough that you can’t store it in your computer’s memory. This is also some very aggressive thinning; taking only 1 out of every 100 samples is pretty crazy. This should only leave you with 10 samples at the end.
Also, you should probably be using RWMH (Random-walk metropolis-hastings) and not MH.