It is true that it is good to do UW random timed blocks, but I also think that at this stage of your preparation you are probably not ready for that as you haven't mastered all the topics as yet. If you're doing random timed UW and don't have a solid foundation, you will still miss the interconnections that UW is teaching. When you feel you have a good grasp of all the topics, you can start doing UW random timed blocks. Don't worry about if your assessment with UW is accurate at this point, you can use the nbme forms to get a predicted score and practice sitting for a long time. I think right now you need to focus on learning the material.
From what you said, it seems that you only used Goljan Path and FA, to be honest I don't know if that's enough. Since you know what your weaknesses are, go through those in detail in FA and maybe pull on another source to help you with difficult topics (for eg Kaplan LNs or some of the other books that are recommended). Keep doing UW questions on these topics to drive home the concepts.
In the month or two before your exam, start doing random timed blocks in UW.
You should see you scores start to go up soon, just keep working at it!