I never did understand why Angelique had self-esteem issues, unless she was really mistreated as a child (which I suppose can be explained in ANGELIQUE'S DESCENT, if you want to believe Lara Parker's version). She was gorgeous, charming, and certainly could have had a man fall in love with her on her own terms. She set her sights on BARNABAS, and he was the beginning and end as far as she was concerned. The problem was, and a spoiler is coming for those who haven't seen the entire 1795 storyline,
even when she blackmailed Barnabas into marrying her, she still didn't trust him or believe he cared enough. When she learned he was giving santuary to Vicki, she was furious enough to make sure Vicki was captured by Trask and removed from HER home. Angelique could never relax, even when she got what she wanted. I think she would have been happy as Sky Rumson's wife, coddled in luxury by a rich man, but that fell apart on her through no fault of her own.
Like everyone in DARK SHADOWS, Angelique was looking for love, but in all the wrong ways, and even when she finally got the man she wanted, instead of dropping the use of witchcraft (which she even told Ben she would after the Jeremiah's ghost fiasco), she couldn't do it, and it proved to be her downfall and the end of her brief marriage to the man she loved. Remember, Barnabas overheard her incantation, which piqued his suspicions and led to his realization that his wife was the real witch.
Love, Robin