Hamilton moved 40 points clear of nearest rival Sebastian Vettel on Sunday with a commanding victory at the Singapore Grand Prix.
Vettel now needs to win the next six races to keep the pressure up on Hamilton.
Bottas is fourth in the drivers standings, a distant 110 points behind Hamilton.
But despite Mercedes’ championship hopes now resting on Hamilton, Bottas says he focused on himself.
“I need to keep hungry and motivated for each race,” he said.
“Obviously mentally for me now compared to the first few races of the season, it is more difficult now to feel that same mentality that you are fighting for the Championship and so on.
“I need to put targets for myself.
“If I just turn up like ‘OK I am going to be here to help’, it’s not ideal.
“I need to have clear targets for each race weekend and that’s what I’m going to do.”
Sky Sports commentator Martin Brundle believes Hamilton is in invincible form as he edges closer to a fifth world championship.
Brundle wrote in his Sky Sports blog: “Lewis Hamilton has shifted into overdrive again and he’s in invincible form.
“After winning four of the last five races, finishing second to Vettel in the other, he has a 40-point lead.
“Just as he’s raised his game so has the Mercedes team, they’ve outscored Ferrari in the Constructors’ title fight for the last five races too.
“Mercedes, then, are once again the dominant force, but it’s Hamilton making the difference.”