Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Air Traffic Control Developmental
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Training / Qualification
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Environment - Non Weather Related; Human Factors; Procedure
I was training on the X Scope and traffic volume was fairly high compared to the previous several weeks.  ZZZ was landing Runway X and ZZZ1 Runway Y Right; making for a complex approach pattern.  Aircraft Y was NW bound toward ZZZZZ; the South fix for RNAV X approach at ZZZ level at 030.  Aircraft X was on the Localizer Y Right approach at ZZZ1 east of ZZZZZ1; descending out of 030 for 020; not cleared for the approach.  The close proximity was recognized as Aircraft X (now at 025; still descending) was established on the localizer and Aircraft Y (still level at 030) was approximately 1 NM away from ZZZZZ; the situation was recognized just as 3 mile separation was lost.  I turned Aircraft X to a 180 HDG as they were out of 022 for 020 to avoid a further loss of separation.Aircraft X was slow to descend and I did not recognize the altitude in sufficient time.  Training has been intermittent for a long time due to the COVID situation.  Also; unusually frequent storms and bad weather had kept traffic volume low for the past few weeks; keeping training complexity low as well.  Today presented lots of training and volume; I was getting tired due to not being conditioned for constant traffic and lost focus.  I would [recommend that I] recognize my own fatigue and ask for training or to work a slower or less complex position for a mid day break or to change things up.
TRACON Developmental reported a loss of separation and cited lack of training in high traffic volume as a contributing factor.