Our NASA counterpart’s Aviation Safety Reporting System sister safety publication Callback Issue 545 featured this honest account from a GA pilot who learned an invaluable lesson for future flights.
I was flying a small aircraft for my first IFR solo cross country. … After departing Jacksonville flying as filed at 6,000 ft, I was asked to descend down to 4,000. I noticed I would be flying straight into the clouds – which by the looks of them seemed fine. I am an instrument rated pilot and current for IFR flying. I advised Orlando ATC [of] my request to deviate from buildups – they agreed. I deviated and then I requested an altitude change to 3000 ft to avoid the large build ups. I requested further deviations for weather avoidance several times but I was denied. I found myself in a rain shower which pushed my plane down due to the downdrafts. I was rapidly descending at this point. My airspeed was in the yellow and the aircraft was getting increasingly difficult to control. While trying to maintain control over the aircraft, I advised ATC my concerns for the safety of flight, requesting an altitude change, I was denied again and advised to fly at 3,000 ft which I flew. I believe if I had requested to stay at 6,000 ft when the controllers gave me 4,000 initially instead of descending down into the worse weather, I might not have broken aircraft separation.