My commiserations to the OP.
Paying too much for an IP is never a good idea and often leads to future suffering. If I recall correctly, many years ago, the OP placed "Want to Buy" leaflets in peoples letterboxes. This sort of strategy is fraught with difficulty and usually ends up in tears. The only people who would respond would most likely want top dollar for their junk. It is truly tragic that the OP paid too much for her property from the very start.
To anyone buying an IP in Frankston: I urge you to concentrate on the cheapest quartile of the market. Doing anything else is totally nutty.
Buying cheap is the most assured way of getting decent Capital Gain. Personally, if searching in Frankston, I would only look for houses at or below $350,000 and not pay a penny more.
Again, my commiserations to the OP. Totally agree with you about the dodgy property managers - they can be a pain. It's always a worry if your own property manager rents rather than owns.... when push comes to shove, you know where their sympathies will lie.