So you're making a 50-75% loss every month? Average power cost for you is something like 0.16 euros per kWh and an average i7 desktop pulls between 140-170 watts at full CPU load. So it comes out as being around 16 euros a month in power usage for 5 euros in crypto. You would be much better off just buying those coins with the money instead of paying for the power to mine them.