"I stand by my call. They know they can't win without me and I know they can't win without me. It's a tough situation."
The controversial 25-year-old cut short his reality TV stint on "I'm A Celebrity... Get Me Out Of Here" after just three nights, citing depression.
Tomic, ranked 168 after a forgettable year on tour, is confident he can return to the world's top 20, dismissing suggestions he is mentally fragile.
"No, no, no. I wasn't like that," he said.
"I got to top 16, 17 in the world, in one of the biggest sports in the world. You can't get to where I got to if you're not mentally strong."
However, he acknowledged a Davis Cup return would be tough, again claiming corruption inside Tennis Australia.
"I'm not happy with that whole situation with Tennis Australia," he said.
"It's up to them to fix ... but we have a few wrong people in that organisation and I hope that can change and the best players can be playing Davis cup again."
Read more: Benji Marshall reaches out to 'depressed' Bernard Tomic
Tomic vowed to resume tennis training as soon as he returned to Australia, saying he regretted his TV stint and "I only became depressed when I got in" the African jungle.
A leading sports psychologist says Tomic must seek professional help to turn his life around and has a chance to follow Nick Kyrgios' road to redemption.
"I think something has happened," Jeff Bond, who worked with Pat Cash before his 1987 Wimbledon triumph, told AAP.
"Whether it was something that occurred on the show or the criticism he has received from people like Lleyton - it can be the most-innocuous thing that will cause someone to turn the corner in their lives.
"Same thing with Kyrgios. Suddenly, he seemed to find a better direction, then received positive reinforcement (from public) and continued to do it.
"Maybe Bernard will do the same thing."But Bond warned Tomic would find himself back in the same dark place if he did not speak to a professional, especially after citing depression on the TV show.
"I am generally concerned when anyone says they are depressed," he said.
"I hope he seeks out a professional to run his thinking by and get some objective feedback, someone he trusts so he can take advantage of this new approach."
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