Every pregnancy is different, as others have said. If YOU feel rubbish, that's how you feel. Some sail through it, others get hospitalised for HE. Nothing to do with coping, it's different circumstances!
When I was pregnant with DS, it hit me at pretty much 4 weeks. I felt awful: like you, was only sick a few times a week... But I felt horribly nauseous 24/7, sometimes just talking would make me gag... The only time I felt ok was when I was asleep. Needless to say, it rendered me useless for quite some time. (It did ease up a bit at 20 something weeks.)
Like you, I felt guilty and like I was being a fraud. I was worried about TTC again, but you know what? I'm 26 weeks with DD and apart from one week when I actually caught a bug, I've worked throughout, and with the commute have been out 7AM - 5PM. I also have a toddler to look after at home, so no chance to rest up in the evenings/weekends. Why? Because I'm lucky enough to have had a totally different experience this time around. I've been tired, yes... absolutely knackered. But there's a remedy for that: sleep. I've been nauseous too, but NOTHING like last time. More like a low-level hangover than the debilitating all-consuming nausea I had last time.
When I was pregnant with DS, I had someone tell me they "were too busy being a mum to suffer from morning sickness", someone else tell me "you just have to get on with it"... All of which made me feel really bad about being so rubbish at being pregnant. I now know that those people had NO idea how pregnancy really can be like an illness.
I'm sorry I've written an essay, it's just that I really feel for you and the last thing you need is to feel guilty or like you're being a wimp.
Rest, take it easy, breathe.... One day at a time, you're closer to feeling fine again. Other people may have been pregnant, and coped "better" - but chances are they really weren't feeling like you are.