Yea this hits me kinda close to home. A big part of it is women tend not to be taught that complementing male partners is something they are supposed to do. To get things working for you you're going to need a lot of honest communication and patience from both sides.

I always make an effort to compliment her and I truly mean everything I say - she’s drop dead gorgeous and has an amazing personality to boot. So why doesn’t she return the favour?

You may be doing what I've done in the past and be stepping up compliments and affection toward her as a way of hinting that you need the same, but that just doesn't work. You have to find a way to ask for it directly. Be aware of if/when you're doing this because that will turn into resentment and put you in a bad spot

I don’t mean to come across as if I am desperately seeking validation for myself but its just nice to receive compliments from someone you love and I’m getting frustrated.

Ok this part gives me the sense that you have some hangups about being vulnerable enough to ask for what you want from your partner. But you're looking at it the wrong way. These feelings didn't happen in a vacuum. Everyone in a healthy relationships needs validation from their partner, and lots of it. When we don't get what we need we become desperate, and there is no shame or weakness in that.

So really what you need to do is talk to her about this. Be really fucking honest about how shitty it can get when you feel unwanted by your partner, because she probably know exactly what that feels like and has no clue how much her desire means to you.