Stress can make sickness worse. You are of course stressed, it doesn't sound like your partner or parents are supporting you at all which is so sad. I know my dh got fed up with the situation sometimes, real life was put on hold for us all really. But it seems a distant memory now. It was worth every minute of feeling horrendous to have our gorgeous babies.
Your partner needs to hear the words from someone else, preferably a professional, tell him how horrendous it can be for some women and that they need all the love and support they can get. Calling you lazy and not bringing you food when you need it is just going to make you feel worse. You poor thing. I sympathise so much.
I completely understand why you are contemplating abortion, I remember mentioning it to the gp too
but I think if I had I would have always been wondering.... what if the sickness had worn off in another few weeks? I would never have known and always be wondering, I know for me I would have regretted it deeply forever more.
You've come this far, you would have gone through all these weeks for nothing? You're pretty much half way! My sickness started wearing off at 17 weeks and gone pretty much by 19 weeks. My dsis was a few weeks later than that, everyone's so different.
Will you ask to try the steroids? It would be amazing if they helped, even if something can help a little it's worth a try, it might mean you can think more clearly and function more.