I've been with my boyfriend for almost 2 years now and at first we had sex quite a lot and then recently it seems to be less and less... sex used to be fun for us and was a bit more than sex but now it just seems really quick and less loving like he can't be botherd anymore but then there are other times when he can't even *** it makes me feel like I'm doing something wrong theirs times when I want sex with him and it seems like a chore to him or he will make up excuses to get out of it... this is making me feel really un attractive and abit upset but if I question him he will say its nothing to do with me that he still finds me attractive etc ijust don't quite believe him and its starting to get me down... I don't no what to do!!

There could be some things that are bothering him that have nothing to do with you. Or he could be losing interest in you. The only way to find out is to get him to talk about this. Sex is great, but being open and able to talk about your issues is also important. Until you get him to talk about this, you will think the worst

Probably you should adjust your personality and wear, talk and do whatever he likes.

How old are you both?
It is always good to know that you're not advising an 11 yr old, and makes it easier to answer.

Using sex as a measure of feelings, is a big mistake, and can't replace good old fashion honest communications.

As tal said, communicate.
Too many factors like stress, being overworked, being worried, can make a huge, but usually temporary ,difference in a persons libido.

When was the last time he had a physical? The problem could be there.

But stop speculating and find out. Communicate communicate communicate.
It can be the prevention and/or the cure.

And don't become a slave to anyone , changing your personality and doing whatever your told to do.
Relationships are a two way street. The give and take should be coming from both directions.
One person trying to become something they are not in order to please the other is a foolish and useless thing to do.

Communicate.

I wish you well.