The Turkey international arrived with a £27m price tag last month and was backed to score the goals Everton desperately craved to climb the Premier League table.
Tosun has so far failed to truly acclimatise, however, starting just two of the four top-flight games he has been available for.
"I am a Besiktas man, it is my home, but it is useful to say: I never return without a battle, without success," he is quoted as saying by Football365. "I hope everything will be better once I get through with the adaption period.
"I am currently trying to adapt to the life in England, my new home. It's a new environment for us after such a long time at Turkey but we're doing okay. It's also not easy to come to a different league having played in Turkey for almost seven seasons.
"It's normal to have periods like this, and my manager Sam Allardyce also told me that. He's always speaking with me. I have no problems. He told me once I get used to it I'll become a starter for the club. I am working hard right now."
Tosun found the net eight times in 16 Super Lig outings in 2017-18 before joining Everton, while also registering four times in the Champions League group stage.