Ah, OP.
I was in about two year relationship when I was 22 with a 42 year old. I wasn't in love with him, but I did fancy him and liked him, and we did live together. Basically, it was fun. He was fun, very good looking, athletic, rich and liked to party. We lived in his penthouse in a city centre, traveled together, partied, went places. Life was a blur.
I don't regret a thing. Contrary to the popular belief here, he wasn't a creep, wasn't abusive, controlling, mean or coercive. I have no scars, trauma or regrets. He hadn't hurt me in any way. He actually did propose, but I didn't want to marry him and we drifted apart.
I wasn't serious with him and wasn't sure I'd like to be with him in long term, so my advice to you would be: don't rush into a 'serious' relationship/responsibilities/family life, DO NOT under any circumstances get pregnant now, and don't make him your 'whole world': keep your job, your friends, your studies, your money. At least for now, for a few years. Until you're REALLY sure. Otherwise I see no problem.
As for the daughter - it could go either way. But I, for one, disagree she will definitely be shocked and disgusted. Maybe so, maybe no. If my dad shacked up with much younger woman - I honestly wouldn't care. Well I'm 36 now, my dad's 60, so hopefully he wouldn't date 20 year olds, but a woman 20 years younger? Or even 30 years younger? Honestly, why would I even care, they both would be adults and my dad's private life/relationships are not my business. Same as my relationships are not his.
That said, I think he should tell her your age in advance.
I always liked and dated older men. Some time after the aforementioned fling I married a man one year older than me. It didn't work, we divorced three years after. Now my partner is again quite a bit older than me. We don't live together, I don't want to. He doesn't 'control me', we both have our money. Life's good and you like what you like.