You sound exactly like me!! I'm 37, met my husband who loved bikes so got involved and then it began! I'm 5'3" and not real strong.
I started with a crappy atomic, just to see if I could do it. Then we got me a WR250F. Well, that thing was way to heavy and hard to ride. So next, the CRF150R. And yep, same prob, the twitchy shitty pain in the arse! Good on an MX track but not in the bush. So we got me a 250r Freeride. Well that thing was awesome. I would not be where I am now had I not ridden that, it just taught me fantastic throttle control and bike skills. It chucked me off early on in the piece courtesy of that throttle grab you describe (I know exactly how you feel!!) And I smashed my wrist in a couple of places. Anyway, I just bought a 2016 KTM EXC-F 350, same as yours. I've had mine lowered in all respects but nothing has been cut so it's all reversible if wanted. I can touch the ground fairly well with one toe and feel pretty good on it. If you want suspension done with no irreversible effects go see Anthony at Boltons in Kyneton. He is brilliant. And I would love to have a ride with you at some stage!!!