To prepare for Neuroscience you're going to want more than just a background in cell and molecular biology. Ideally you're going to want to take at least one semester of Organic Chemistry, Biochemistry, and Statistics (though that's probably already a requirement for your psych degree anyways). I can give you the list of requirements for the neuro degree I'm working on now if you want.
You might also be more interested in cognitive neuroscience. A more systems approach at understanding higher cognitive processes through the lens of the physical processes at work and their interplay.
If you can manage through a semester of Neurobiology, which heavily focuses on the cell biology and chemistry of neurons, synaptic transmission, dendrite function, plasticity, etc... then Neuroscience is for you.
Here is the link to wiki for the Neurobio course I took. I think you can access it, if not feel free to message me for a way in.