I remember saw this movie on TV long time ago but I don't know the name.
Its about a stage actress whose husband is a theater director or something like that. She's having affair with a young man name Tom (or Ben) but he is just a gold digger and a younger actress is intending to take all of her glory

Sounds like

The Roman Spring of Mrs. Stone (Original film 1961)

Karen Stone (Vivien Leigh), an acclaimed American stage actress, and her businessman husband are off on holiday to Rome. On the plane, her husband suffers a fatal heart attack. Karen decides to stay in Italy and rent a luxury apartment in Rome. The Contessa Magda Terribili-Gonzales (Lotte Lenya) soon introduces her to a young Italian man, Paolo (Warren Beatty), who is actually a highly professional gigolo. Karen and Paolo begin an affair, but it soon becomes obvious that Paolo is in it only for personal gain. He is soon bored by Mrs. Stone, and leaves her to pursue a young American film actress (Jill St. John). Ridiculed by the Contessa, chastised by her friend Meg (Coral Browne) and abandoned by Paolo, Mrs. Stone is soon utterly debased enough to surrender herself to a ragged, mysterious young man who has been following her obsessively. In the end, it seems as if Mrs. Stone has literally given up her life.

Remake

The Roman Spring of Mrs. Stone (2003 Tv movie).
Starring Helen Mirren

A failing star is faced with a life-style change when her rich husband suddenly dies while they are en route to Italy. She then sets off in a series of flings with gigolos found for her by an aging contessa. Each contact spirals further out of control until she becomes obsessed with one young man, who initially treats her well, but then with disdain.