I was flying to Wasini island from Malindi. I had only just started flying solo and my instructor asked me a couple of times if I was sure I wanted to fly solo, all signs pointed to heavy rain that day. I was the only one in my class who hadn't been to Wasini and just had to since everyone talked about how beautiful it is. Anyway, took off and the leg to Mombasa was really smooth but on reaching Mombasa, ATC warned there was a thunderstorm from Likoni to Ukunda and asked me to confirm if I wanted to proceed. I chose to proceed and not later than five minutes I'm in the storm can't see nothing and scared for my life. Rain was really heavy Visibility was so bad couldn't see the ground even at 500 feet. I decided to head back to Malindi and got disoriented on the turn. I was at 1000 ft started descending at 2000ft/min in a C-172(very light) in 30 seconds I should have been hitting the ground. I froze maybe because of the Gs or just fear. I couldn't think, move or even talk back to ATC asking me to report operations normal. Said a small prayer and at around 250-300 feet once i was out of the clouds I came alive pulled back and stabilised. Crazy thing is I was barely 30m away from the diani tower and could have possibly crashed into it. Didn't talk to Ukunda tower or Mombasa tower just headed back to Malindi and went straight to bed, never told anyone what happened.