My younger sister is 21 years old. She has some learning and communication difficulties, similar to Asperger's, but mild enough that (with a lot of extra support from family and university mentoring) she is completing a degree.

4 1/2 years ago (Feb 2008), aged 17, she got into a relationship with a boy of the same age, with similar learning/ communication difficulties. For a couple of years they were happy (albeit a bit inappropriate in public imo) but in July 2010, my sister decided to end the relationship (amongst other things, he was I believe pressuring her for a physical relationship she did not want).

Obviously following the break-up she was understandably upset, but went to uni as planned to start her degree. 6 months later (Jan 2011), he contacted her, asking if she wanted to meet up. She agreed and they met for coffee. He asked her if she wanted to get back together, to which she replied no, and that she hoped he would meet someone else, and be happy. A few weeks later, he did.

Ever since then my sister has been fluctuating erratically between enthusiastic texts wishing him and his new gf happiness, angry Facebook messages demanding why he started going out with someone else, and desperate pleas for friendship. Last summer she went on antidepressants. In my opinion (I have depression, but am not a doctor or anything) this was not the suitable medication for her. It isn't a chemical imbalance, it's a reaction to the break-up. She has also had counselling, but it doesn't seem to have helped.

Despite the relationship ending 2 years ago, and the new relationship starting 1 1/2 years ago, my sister still firmly believes that the new relationship is wrong, and that they are not meant to be together the way she believes she was meant to be with him. She still sends him erratic texts. He has now blocked her on Facebook. If I had any say in the matter, I would have deleted his number from her phone a year ago and ended this madness, but my family will not let me. Last summer we tried to persuade her to remove his number from her phone (but leaving it in the family phonebook in case of "emergency"), but she refused.

This has now been going on for a year and a half. Up until last summer I was still away at uni, so missed the initial traumas. As a result, my sister refuses to let me try and help her at all. I am excluded from any conversations about her wellbeing. My mum and me have similar personalities and get angry at these outbursts. My dad is a constantly chilled out person, who tries to help but doesn't really say the right thing. My older sister is the only person my younger sister will talk to. They spend hours and hours together going round and round in circles. It is taking a massive emotional toll on my older sister, who now feels that she also needs counselling in order to cope with it.

I just want it all to end. I also have depression and my sister's outbursts are triggering me as well. I wish I knew a way to deal with this situation. I love my family and I just want them all to be happy. I am scared that this will never end, and we will never be happy again.