If you don't know the passcode and can't get into the phone, then you have no option but to force the phone into recovery mode and restore. You WILL lose all data. No way around this.
Photos should have been imported as soon as possible after they were taken into your computer for safekeeping. Data should have been backed up frequently to prevent data loss in situations exactly like this.
If you have not been using your phone as recommended, then data loss is inevitable, as you're finding out now.