Hi Sichez,
Sorry to hear that you are struggling. I'm in the same situation at the moment, having evicted my previous tenants for none payment. Make sure you cover yourself against this. I have had plenty calls from people about my house, where I have not been convinced that they are in a position to pay.
I would say around 350 - 400 Euros per month is about the going rate there.
To get an idea of what the going rate is, use google.
and search "se alquila forentera del segura"
Put up a large Se Alquila notice (You'd be surprised how many go up where the phone number is unreadable).
I'll compile a list of places where you can add your property to rent for free.
Hope this helps
Will