Feeling lonely, insecure and abandoned.

I have been feeling very lonely and insecure of late. I was in a relationship a few years ago which ended in a break up. Ever since, I have been feeling deprived of love & affection. I feel so upset all of a sudden for no reason. I find it difficult to keep my emotions under control. If I am very affectionate to someone, I expect that person to treat me the same way, and when they don't, I find it very difficult to accept it which affects my sleep & concentration too. Because I am afraid of feeling hurt by people I get closer to them, I try not to not get closer to anyone which makes me feel even more lonelier. My parents love me greatly but I dont. I also had a surgery 5 years back, and since the surgery I have become severely underweight (I am 27 years old and I weigh 46 kgs) and even the smallest of physical activities seem to take a toll on my body which makes me feel insecure about my health. All that I think of now is that being born is a curse and I can't do anything about it.