Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 3
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Human Factors
Aircraft Z was climbing out of 8;000 feet for 10;000 feet and higher with the Center. Aircraft X was switched to Center frequency north of HSV airport. Aircraft Y was climbing to 10;000 [feet] westbound. Aircraft X apparently heard the wrong Center frequency and subsequently never got a higher altitude. A few minutes later; Aircraft X called back to verify the frequency and was re-given the correct center frequency. At the time; Aircraft Z was inbound at 11;000 [feet] from the west so the Center could not climb Aircraft X since his communications switch was delayed due to the wrong frequency. Since Aircraft X never got his climb; Aircraft Y was on a conflicting heading with Aircraft X; now level at 10;000 [feet]. Center called to ask what was going on. I immediately issued a 180 degree turn and called traffic to Aircraft Y to increase separation. I am unsure of the distance between Aircraft X and Aircraft Y when the turn was given; it appeared to be less than 5 NM. The volume of traffic was high and the complexity was avg. There were numerous VFR pop up aircraft and military practice approaches at the time of the event. The airspace at HSV should be split off (east radar and west radar) more often but we cannot due to staffing. Our minds are not 100% where they should be because we are having to worry about money. We are not being paid this week and I have numerous bills. I am check to check and this added stress could be a factor to me not seeing the conflict.
Huntsville TRACON Controller reported a loss of separation due to one aircraft not hearing the climb clearance.  Reporter also stated position should be split; and was worried about money during the government shutdown.