Well done for being so active with property from such a young age, I wish I had been!
One observation I will make is whether your goal is meaningful and clear for you as written?
15 properties worth >80k each giving income (gross or net?) of 600.
What part of this is truly important to you? Portfolio value, gross income, number of houses? If you can write that down clearly it should give you focus.
For an example my goal is a level of net income each month that matters to be able to build a portfolio at a rate that supports financial freedom. That allows me to break down the big goal into smaller, more manageable ones (e.g. save more money for a deposit for house #1!)
Hope that helps.