((((HUGS XENKO))))
I'm very sorry that you feel like the people you trusted let you down that is always a horrible feeling
As far as lying goes..I believe at some point or time or another everyone has lied about something.even if it was just once and about something seemingly small or unimportant...does it make it alright??.. probably not. And ESPECIALLY NOT IF THE PERSON WAS DOING SO FOR SELFISH REASON KNOWING THAT NOT TELLING THE TRUTH WOULD/COULD GREATLY HURT ANOTHER...Lies lead to mistrust. Honestly is always the best policy, but there are occasions where people do lie unselfishly. These lies are generally taught to us by society. Manners for example.
If you are invited to dinner at someone's house. And this person spent a lot of time and hard work to put a meal on the table. Even if you are chocking down every bite bc it's horrible or something that you hate. You still eat it a graciously as possible and thank the host for a wonderful meal! Is this a lie? Yes. But does it make you a liar or a bad person. Absolutely not! In fact, quite the opposite. Because you are not lying to gain anything, hurt anyone, or get away with anything...you are only thinking of the others feelings completely. That kind of lie is not wrong.

Another ex: Christmas is here. Someone gives you a present. They watch you open it with great anticipation and say" I saw this and thought __ will love this.." and so what if you don't like it are you going to say so??!! Saying you love it is a lie technically but the other person put time and effort into picking it out and it would only hurt them to hear you say they got it all wrong. Do you say thank you it's lovely! That is not wrong. Do you know how many of us have worn items made out of elbow macaroni??!! And told our children how much we love the necklace, bracelet, tie pin etc...?? Of course these things are not a fashion statement we would see love and buy for our selves ever! But are you going to tell the child you think it's hideous?! And not wear it? Not say you love it? Not say it's beautiful??!! Of course not! Are you lying when you say how much you love the item its self? Yes.... But, when you say you love it and it's beautiful and wear it. You are honestly saying I love you, you're beautiful, and I'm proud to be the recipient of a gift of the heart!

Do I agree that unfortunately too many people lie without good intentions?? Unfortunately yes. A lot of people do. Good people regret these lies. They eat away at their souls. They come clean eventually if possible and apologize..or they try to make up for their short comings in another fashion.
Some people tell lies but don't intend to hurt anyone, but unfortunately they can be shortsighted and not able to see at the time how they hurt another If someone you care about does that. It's best to tell them that their action statement etc..hurt you. Otherwise resentment and mistrust will grow. People too often in today's world are so busy worrying about their own crap, that they simply are ignorant to other's needs and feelings This does not make them right but it doesn't nesacarily make them horrible bad people either.... it just makes them human I guess??...

Then there are lies that people convince themselves that they are telling to Not Hurt the other person, and most people who tell these lies truly don't want to hurt the other person, but in fact they all ready have, and the lie they tell is to cover up their misdeeds or avoid further damage...there is some selfishness in these lies, but depending on the situation lying may be the best course of action. This is greatly dependant on the situation...
Ex: A spouse cheats or to some degree goes outside the boundaries of their relationship. This person may carry this indiscretion to their grave in order to save their marriage, and convince themselves they are doing this for unselfish reasons. The act was selfish and the lie is not completely unselfish either..so is the lie right or wrong? Most likely wrong. But depending on the situation and the true nature of the person...if they are truly sorry good and remorseful...they will eventually either end up telling their spouse the truth or if it is never called into question...they may hold their wrong doing inside and learn from it and hold themselves to a much higher standard to make sure they never stray again. I personally don't think the second course of action is ever right, but I can see for others where it may be. Not everyone's relationships are the same and some people would rather never know.. so in those people's relationship the lie may be for the best for both of them.
But if the spouse feels something is amiss and asks the other or stars to feel mistrustful and the cheater still lies then that is WRONG, HURTFUL and SELFISH!

But then look at a relationship that is already for other reasons ending.... one or both parties,are already done, angry and/or hurting greatly from the demise of their relationship... One party packs their things and is walking out the door..then turns around and says "oh! And by the way...I cheated on you too."..this may be a situation where telling the truth is a selfish act that only serves to further harm the other.. so in that situation maybe telling truth is wrong and hurtful malicious and spiteful and just plain unnescary. If it were me I'd want to know the whole truth regardless of the pain it may cause me...but that is my personal feelings..others would not want to know.

And then there are just bad people who do bad things and lie about them without regard to anything but their own selfish needs or self preservation.
And there are others who are not bad people but because of their fears and life experiences have developed lying as a defense mechanism. Is this wrong?? Yes...but most likely they know it is wrong and unhealthy...and hopefully get help to break this habit and find better healthier defense mechanisms.

So I guess the moral of my TL;DR rant is this...just like everything in life...lies run over a very broad spectrum. And it is a harsh judgement to label a person a liar without more introspection.