Dont give up!
Outside of the fertility issue, take a good look at your incubator and do the incubator cleaning as suggested......ooops to late you done set the eggs. LOL
As for your incubator, two important things you might want to check as I think many overlook this in DIY Designed Incubators:
1) the need for freash air. Most DIY's tend to build an incubator and think that an incubator needs to be air tight and it does not. It needs to replace air (while it incubates). As eggs/embryos develope they (need) breath in the oxygen through the shell... constantly. Of course the by product they breath out is carbon dioxide which needs to be removed, else the eggs/embryos suffocate. So adiquate air holes are needed.
2) Another cause of dissappointment is having the eggs too close to the heat sorce or a too intense of a heat. Thus the egg will absorb the radiating heat and get hotter than the intended ambient temperature surrounding the eggs or that which the thermomter is reading. Just think how hot your hand gets if you hold it above a stove cap for a minute. Even on a low or medium setting.....after so long your hand is still warmer than intended. So make sure that is not the issue and if it is place a heat sheild between the heating source or elivate or move the eggs further away from the heat.>>or try to use a lesser power heat source.
You want a warmer air, enough to heat the incubator, to reach the desired ambient temperature (99.5-101.5), but not such a heat that it will cook the eggs. Subtile heat is better than intense heat.
Oxygen, Heat, humitdy, viable fertile eggs... done correctly should = chicks.
Wishing you luck.