Here, I demo how to use MATLAB to get the transfer function of your overall block diagram, and to save yourself some tedious calculations...the last image of video shows the hand calculations, which results in the same answer.
-make sure you have the Control Systems Toolbox from Add-Ons
-parallel blocks in same direction are added
-series blocks are multiplied by one another
-parallel block in feedback, use loop gain G/1+GH formula