A lot of people have the misconception that objective morality means that there are certain things that are right or wrong, regardless of the situation or context.
They also usually have a misconception about what morality is. Their idea of morality is something like: there are specific rules that if you follow, you are 'good', and if you don't follow, you are considered bad.
Many people think they are relativists because of this, or they decide to adopt a moral philosophy like Kant's Categorical Imperative, or that morality comes from God -- they adopt philosophies that are rule-based.
But in reality, 'morality is objective' means 'in any given situation, there are choices that are better or worse than each other, and it is a matter of fact that some choices are better than others'. It isn't a bunch of set rules like 'killing is always wrong', because there is always the possibility of there being factors in any given situation that would make things usually considered wrong OK to do. For example, killing might be justified if, say, a serial killer was coming at you with a knife, and the only reliable way to survive was to shoot him.
It would probably be less confusing if everyone just called morality 'choice theory', because that's all that it is: morality is the theory of making decisions.
Some people use the word 'morals' to mean something more like 'the things I think I should do/believe, but actually don't'. Someone may refrain from doing something socially unacceptable -- such as being promiscuous -- 'because of their morals'. They might still want to be promiscuous, but have decided it is 'wrong', and so don't do it.
This is missing an important fact about morality (other than, y'know, morality isn't about blindly following rules, it's about making good choices): Morality is what is actually good to do -- not just what the culture or peer pressure says is good to do. And 'what is good to do' is not just good in general, but good for you.
In other words, behaving morally should not be an unpleasant experience. It shouldn't be something that you do because you feel you have to, or would feel guilty if you didn't. It's simply about making the best choices, and the best choices for you usually include making you happy.
If you make a choice and feel bad about it, that's a sign that either you don't understand why it was the best choice, and so aren't fully persuaded, or the choice was the wrong choice. If it's the former, you should try to understand it better and work out why you might still feel bad about it. If it's the latter, then people make mistakes and that's OK, but consider how you can avoid the mistake in the future.
Related links: Choice theory; dialog about morality.
