i no longer find my gf attractive

we been together about 2 years and live together 1 year, at the start is good and she was a little fat but for the past year she put on so much weight that i almost not able to find a girl fatter than her on the street. she never told me her weight but i believe is close to 80-90kg and she is 160cm short

i put on some weight too but nowhere near as much as her. sex used to be good i l1ck her all da time and she used to approch me and play with my @#$% and BJ, that gets me excited. but for the past few months she no longer BJ to the stage that i actually have to ask. but only thing she will do for the past year is let me lick her and and then i have to 'get it up' without any help from her side. she still wants to have sex but i no longer wants to have sex. a lot of the time i can't even get erection. and seeing all the much better body girls out there it's make me even less want to hav sex.

however, she is really nice girl looks after the house and looks after our dog, and she still wants to have sex. but i simply can't perform by just looking at her. her idea is that it's my duty to get her excited and then we can hav sex but problem is i am never excited.

what should i do, she wouldn't lose weight still eating like crazy, and we are growing apart so quickly,

Ok... chances are she feels really bad about getting fat, and she feels very insecure.
Her self-esteem has dropped tremendously, and she is eating to help cope.
Gaining weight would definitely affect sex.... and men often complain about their women being less sexy after gaining weight.
Now you have to decide if this is a big enough issue for you. It's not just about looks, but health overall.
If you think you have a future with this girl, you have to make her lose weight. You have to lose weight with her, as support.
If you can't imagine long term with her, then just break up and find a thinner girl. Losing weight is difficult, so you should
give her a really good reason to lose weight.

I know this is pretty mean things to do, but if your in a relationship, good communication and understanding is required.
Anyhow, you should talk to her and encourage her to lose some weight...
Maybe you two can lose weight together and be fit together. Go for a walk, play sports together, eat healthy meals together.

If you have put on weight too, there is a potential health risk occurring. What happened? Did you move in together and just stop doing anything other than eating crap?

Tell her you are concerned about your health and hers. Tell her that you'd like to start walking with her more and to eat healthier. She will probably accuse you of thinking she is fat and the proper response to that is 'no, I just want a long happy life with you and I don't think we'll get there if we don't start looking after ourselves.'

If you want the icing on the cake tell her this story.
A friend of mine had a fit seemingly healthy 19 yr old son who played soccer at a state level. He ate a lot of crap but figured because he was active he was ok. He suffered a massive heart attack in the change rooms after a soccer game. The autopsy showed his cholesterol levels were through the roof.

I hope you can scare her into looking after herself.

I have to rant here. This overweight issue is my pet peeve. Actually, it's not about weight, it's about being lazy, or passive. While Kaius took the positive route, I'm taking the blunt route.

Ok, sorry I have to be so blunt, but I see this a lot. I'm very active in addressing problems in my life. I even had to lose weight 2 years ago and I kept it off, so I have no sympathy for people who whine about being fat and don't do anything about it. Having a baked chicken sandwich with EXTRA MAYO is not the way to go about it. (True story, I saw it myself.)

When my doctor asks a patient to lose weight, only 10% do it. There's your hard facts. She's fat, she doesn't care, she doesn't care about what you think, and statistically speaking, it is unlikely she will lose the weight. Really, you can try to help her through this, but you are not her therapist, and this is such a major issue, I don't think there is anything you can do to motivate her. Support her? Yes. Motivate her? No.

There's a reason why 60% of Americans are fat or obese. They just don't care. Politicians won't say it because they need the votes. Psychiatrists won't say it because they don't want to "hurt their feelings". God forbid a psychiatrist actually motivates someone for positive change. A doctor won't say it because he needs to keep his patients to pay the bills. But what else could it be?

Don't give me the crap about 60% of Americans are fat because of low self-esteem. If you are lazy, admit it and change it. I was fat, I ate poorly, and I didn't do the right exercises or enough of them, so I changed my lifestyle. It has nothing to do with low self-esteem. Whether you have low or high self-esteem, you are sane or crazy, you can still make life style changes to improve yourself. Stop making excuses and just make that change.

Now I'm off to work out.

EDIT: A woman who is 300-400 lbs is pretty common in the US. Don't know about where you are at. 90kg = 198 lbs. You have a pretty light woman there compared to Americans.