Please help me to identify this movie's name:
The good guy finds an excellent woman. Everything is perfect until he discovers that nobody knows her in her alleged hometown. He secretly travels to her hometown to look for the traces of her but nobody knows her picture. He becomes suspicious and continues to do research about her.
Eventually, the good guy marries her (she is very clever). After a while she behaves differently, aggressively, doing absolutelly nothing good for the relationship. The guy is desperate and tries to discuss it with his best friend all the time. Later on his wife increases the humiliation and reveals she cheats him with his best friend all the time and telling that his friend is better in sex, bigger everywhere, laughing at him etc. The guy gets totally depressed as his wife increases the pressure all the time.
Then she pretends that her husband abuses her and the court decides that the good guy must undergo psychiatric detention. It is a trap set on him by his wife and ex-friend to get his wealth and take over his business. By the power of money and her personal charm everybody suddenly betrays the good guy and it seems he will spend the rest of his life institutionalized among the psychiatrically ill people while his wife bribes everybody around him and is enjoying the high-life with his ex-friend.
The good guy is considered as mentally unfit, locked forever but he comes with an idea to pay them back. His wife needs to finish the take-over of his business and she visits him at the psychiatric detention to prove something for the court purposes. Good guy is prepared, pretends that he is "cured" properly. It is his wife who is in trap now. The good guy kills her (choke) in the detention garden behind the tree as a revenge (as mentally unfit = free of charge). Then the movie shows the happy-end as the good guy is considered by a psychiatrists' comittee as becoming "healthy", soon to be released.
The movie could be US/UK/CAN/AUS origin, it is from 80s/90s. I saw it in a TV cca 15 years ago.