Bastianini was rewarded for winning the second-most amount of grands prix in 2022 with a step-up from Gresini to the factory Ducati team this season, and was expected to vie with new teammate Francesco Bagnaia for the title.
But a major shoulder injury at the opening weekend in Portimao scuppered his hopes.
"There were two critical moments,” he told Sky.
“The recovery from the shoulder injury worried me a lot.
“I wasn't able to regain strength, my arm sometimes fell asleep on the bike and it had never happened to me.
“Since Barcelona things improved, but I relapsed.
“I sat in the wheelchair for 20 days, I was very angry, I didn't want to talk to anyone, I didn't want to do anything.
“I hit rock bottom, but from there everything was easier and it was nice to be myself again."
During Bastianini’s struggles it was rumoured he could lose his factory seat to Jorge Martin, who was jostling with Bagnaia for the title.
"I must admit that of all things it is the thing that has made me suffer the least,” Bastianini reacted.
“I have never doubted my abilities, if I am in good shape and enjoying myself.
“Jorge [had] a wonderful championship, but I believe that without injury I too could have fought for the title. I'll try again next year."
A nightmare debut season in the factory team suddenly exploded into life at Sepang, where Bastianini won his only race of the year to deliver a much-needed reminder of his qualities.
"Intense and unexpected,” he described it.
“I knew I was back fast, perhaps to fight for the podium, and instead... the victory arrived.
“Yes, in the evening we celebrated, we were all together with the team, we did a bit of karaoke. .. We had fun!”
Oddly Bastianini won in Malaysia a week after starting the Thailand MotoGP from last on the grid.
"I know it may sound a bit strange, but I almost don't remember starting last,” he said.
“Because I didn't have any problems and honestly it was embarrassing.
“I realised I had the wrong approach, that there was something wrong with me too.
“So I went to Malaysia with a different mentality, more determined. Aware that I could do well, also because the race in Thailand didn't go badly."
Bastianini also switched crew chiefs this year, and has now completed a year alongside Marco Rigamonti.
“Even in difficulties we have always overcome them,” he said.
“We have never argued, we always go in the same direction.
“Sometimes we got nervous, but we are okay when things don't go well. Now that the victory has arrived the atmosphere is much more relaxed."