Thank you for putting up your problem to Healcare Magic!
Your problem is two fold.
Your body weight and the pregnancy
and your husbands extramarital adventures.
You should understand that a body weight of that range for females is morbid obesity
and over that a pregnancy is surely a high risk pregnancy.
You should have been a bit considerate before becoming a centurion.
Men hardly find bulky ladies interesting and over that is the pregnancy... That has led to your husband astray.
Anyway it is not fair on your husband's part. Pleasures should not come in the way of his duties.
He has got a moral duty to support you in the difficult times rather than pursuing the trifling.
Please talk to him early before he is too much involved in the other lady.
Make him known of your concerns and that you plan to cut down on the weight soon.
Take a nutritious diet but low in calories so that you can loose weight safely. Ask your dietitian to plan it for you.
I hope this information would be both informative and helpful for