A student pilot entering the pattern at GYR at night reported an NMAC when their turn to avoid one aircraft put them into conflict with another aircraft they were not aware of.

Narrative

Close call with other company aircraft in traffic pattern on Common Traffic Frequency .I (commercial student pilot solo) was entering into GYR on a 45 left downwind for Runway 03; when a helicopter took off prior to me entering the traffic pattern. As the helicopter departed; it was heading in my direction; as PIC; I made the decision to do a 360 turn before entering the traffic pattern to avoid a near miss with the departing helicopter. While making the 360 turn; Aircraft Y was directly on my tail. I vocalized prior to doing a 360; that I will be conducting the maneuver to avoid the departing helicopter. However; while in the turn; traffic system vocalization occurred as Aircraft Y was still flying directly towards me without acknowledging my vocalization of conducting the turn. Both my aircraft and Aircraft Y came very close; until Aircraft Y decided they were also going to do a 360 to avoid a mid air collision. My turn was a 45 degree bank after seeing Aircraft Y was heading directly towards me. I submitted this safety report in hopes that better; common traffic awareness is seen from this example.