Theres not always a happy ending is there?

ive been single now for nearly 3 years as my fiancee left me when i was 6 m onths pregnant. it was hell to say the least but ive muddled om and got through with the support of fab friends and family. ive become a more well rounded, wiser, independant person...someone i never thought i could be. i own my home and have a reasonable job. Im also divorced as i married young, he cheated on me and i chose to leave as i couldnt live with what he had done. so here i am 34 and single with two children by two different men. Now even though its not a major issue for me, i do wonder however whether this is how it will be forever, and as i am so busy with my sons i do not have much of a life outside them, but have i become so set in my ways that i will never let anyone in again ?? i often think there is something wrong with me as i dont desire a relationship but on the other hand i dont want to think i will be like this forever? i also think ive become too self sufficient that i dont need anyone either, but this isnt normal is it...i mean surely we all need somebody in o ur lives? im just so confused and would love to hear your advise, stories or positiveness.