The Finn had a solid start to 2017 in retired Nico Rosberg’s wake and was re-signed for 2018, but he slumped in the second half of the season.
“The season has been tough,” Bottas admitted to The National, insisting that Mercedes was pushed hard by both Ferrari and Red Bull this year.
And with his teammate Lewis Hamilton winning nine races and the title, Bottas admitted his tally of two wins is not good enough.
“I was definitely hoping for more,” he said, “but I am glad I have proven myself and the team signed me up again for next year.
“I couldn’t beat him (Hamilton) this year but I am working on my weaknesses.
“Next year’s going to be the same thing. I need to again prove if I am going to stay with the team for a long time.”
But notwithstanding his resolve to improve, Bottas said he has always felt the support of the Mercedes team.
“I didn’t have many issues with pressure as I felt the whole team was behind me,” he said.