Dressing up is not the problem here. He doesn't come near you, you said.
Whether u are fat or not, he has to give you your rights.
You said he was religious. So he should accept it, if you have a problem and you wish to see an imam for advice.
I don't know if you are practising yourself. If your husband is practising, then he would respect you more for you learning and practising Islam more.
So firstly know that Allah sent a messenger to you, the Prophet Muhammad.
So learn about the message that Allah sent you.
If you are not learning about Islam then, it is as if ,Allah your Lord, who gave you life, when you was nothing, and Who provides everything for you, sent a message to you, but you don't want to know what that message is.
If this is the case with you, and your husband is practising, then it may be the reason why Allah is not providing the blessings in your marriage.
Know your Lord, Allah, Who provides your food, and follow what message he sent you. You are aware of the Quran, and Islam, so find out the message Allah sent you.
Secondly, if your husband wants you to dress and do your hair nicely, ask him to buy you some clothes which he likes, and ask him to do your hair.
Thirdly, you CAN lose weight.
What you need to do is eat foods that will fill you up, with less calories.
Those small packets of noodles, koka,maggi noodles. Break the noodles into small pieces. Put it in a small bowl. Pour boiling water over them until covered by 1 cm. Pour the packet of soup powder in. Mix it.
Wait for the noodles to soften. Then eat the noodles. Drink all of the soup, and see if it fills you up.
It'll fill you up, and you would only have eaten 390 calories.
You can also put in a couple of teaspoons of canned sweet corn or canned diced vegetables, or cooked prawns. It'll still be 400 calories.
For snacks when your hungry make half a packet and eat that, and drink the soup. It'll be only 200 calories.
Aim for 1600 calories a day.
Don't drink juices or drinks, apart from diet drinks as there are only about 10 calories in a whole can.
Buy a mini stepper, do some exercise.
Watch your weight every 3 days and inshaAllah your weight will fall off.
You gotta watch your food, try that noodle diet for a week, and don't drink drinks apart from water and diet coke or something.
No chocolates, croissants, bread with butter, cereals, curries, fried chicken, pizza.
Check you weight, and after a week check your weight, inshaAllah the weight will come off.
Please try that noodle diet for a week, but you must drink all the soup, to stop you getting hungry.
You might need to sprinkle some salt to make it taste good.
Remember to keep within 1600 calories a day.
Also please have a read of that book I sent to you before.
The etiquettes of marriage by sheikh Albani.
You can download the PDF in the following link.
May Allah help you.