I have obviously no idea about what your HH (horrible husband) is thinking. But a thought came to mind, and I can't shift it, so I will just let you know what it is OP. I am wondering if someone at work, or his dad, or a "friend" of his, has been saying things about your weight/size it could have built up in his mind, and he has let it suddenly embarrass him. Once he started to feel embarrassed about you that emotion could have taken over, and before this, even as recently as Valentine's Day, he was genuinely attracted to you, but he now believes whatever poison this person is saying, and on Saturday morning, and on and off since then he keeps on remembering it, then forgetting it again, in a vicious circle.
Even if my suggestion is anywhere near the truth he should have absolutely not been influenced by it, even if it was by his even worse HF (horrible father).
I should have changed my name for this continuation, as anyone reading it will probably think I have completely 'lost it'! Many years ago when I was going out with my now husband, I would occassionally dream that we had had a big argument, and I would wake up cross with him. He could tell that I was in a mood with him, but because I knew I was being very unreasonable I would only say "nothing" if he asked me what was wrong. I know that having your partner deny that anything is wrong when there obviously is, is very frustrating. Later on in the day I would explain what had happened and we would end up laughing about it - thank goodness. It didn't take him too long to realise what was happening, when we had gone to sleep happy enough and yet I woke up in a cross mood the next morning. So he would ask me if I had been dreaming again and what he had done wrong in the dream, he would then apologise for whatever it was and we would both laugh! It is a very long time since I had one of those dreams. So I wondered if someone has been mentioning about your weight to him, whether he could have dreamed about it on Friday night, and anything can happen in dreams, lots of people could have been making fun of you, you could have have appeared 10 years older and 3 times the size you are now, and dreams can be so realistic, that it played on his already hidden worries - after all dreams do often come about because of underlying concerns.
If by some strange fluke your HH did have a dream like that, because someone has been dripping malice in his ear, it does NOT give him the right to feel like that, or to burden you with it, but it just might explain why he woke up in a mood on Saturday, with a seemingly big change in character. Sadly, I don't think this is something that either of you will end up laughing about. I think that if he is ashamed of you (and please remember that he has NOTHING to be ashamed about, you are beautiful, he normally thinks you are beautiful, and if the statistics are to be believed, you are actually under the average British woman's size) you will need to decide whether you want a clean break from him ASAP, or if both agree, you could try couple counselling. Please, don't lose weight for him, size 14 is fine, it is not overweight and I strongly believe that losing weight for him, not for yourself, would be the worse outcome for you.