As said, student/trainee pilots can experience motion sickness and this topics has been discussed 'ad nauseum'. Funny that you didn't try to have handful of lessons before working on the exams/theory as much, considering your other motion sickness experience on the ground.
While there's reason to be upbeat about body/brain getting used to flying and associated turbulence/loading, not so sure in your case of being sick in various moving vehicles.
How have you dealt with car/bus/ride upset? Can the mitigation be applied to flying? For some, not enough looking outside (ie brain getting confusing signals, looking at lap/book/seat in front) triggers it. For some, the turbulence/bumpiness.
Does your sickness get worse if worrying about it?
For most people, it's only/mainly flying that can make their stomach upset, not cars. I'd say 99% of those would do just fine if they stick to it and relax and take it as our 'reptile brain' (the basic animal part) needs bit of time to adjust to weird sensations/visual/sensory cues.
Having said all this, I had student who'd get queasy under hood if doing anything but S&L and gentle turns without much thermal turbulence. I also read about and talked to one pilot in person, who could not work as flight instructor (often first job in helicopter arena in the USA outside military) because he'd get queasy if not flying hands on himself.
So, not in order:
Step 1 - go get proper lesson in front seat and FLY the aircraft (except the stuff FI has to do initially)
Step 2 - take the queasiness as 'rite of passage' with your sensitive body and just something to overcome gradually, NOT DEAD END TO YOUR CAREER PLANS. That'd just stress you more in cockpit and exacerbate things.
Step 3 - identify/try some tricks that help with sickness on the road. Look out, chat with FI, hum a song, whatever does it.