I think it all boils down to the person, my personal outlook is that of course your parents break up will affect you but its the things that happen after that cause the problems, maybe they were too open about how they felt with you which is why your siblings and yourself have a negative outlook on relationships.
My mother cheated on my father with his brother and i could be my uncles child really, then she got with said uncle, broke up with him and had and affair with her best friends husband... I used that to my advantage so i dont do the stupid things she did..
this is normal, to get past it there are a few things you can do, you need to realize that you can not brush everyone with the same brush, people make mistakes, putting pressure on your relationship because of your past experiences will cause problems, you need to relax as hard as it is (I know how hard it is) remember you chose to be with this person, the same as your parents did, they may feel they made a mistakes but that was their choice, not your burden to bare... They are old enough to choose their lives, you do not need to feel responsible, at the moment you are using them as an example for your love life as are your family, remember if you find someone that loves you and its right you will know it, the worries may still be there but you will know it is nothing to worry about