“I'm going to have, in practice, no more control over my own destiny if the UK is out of the EU (being 1 person in ~50 million)”
I think you’re missing the point, jim.
In restoring the UK’s full sovereignty (i.e. by leaving the EU) it will be simply the UK Parliament that determines matters for the UK. That Parliament will have been elected by the process which has held up fairly well for some time and will involve you and all the other UK voters. The Parliament will, we hope, act in the best interests of the UK and that will be their sole concern. If not, you (and everybody else) will have the chance to kick them into touch every five years.
By contrast, even if the EU Parliament were a proper forum (which it’s not for reasons I’ve pointed out in the past) that Parliament will not necessarily act in the UK’s best interests. There are another 27 nations to worry about, all of whom will have different priorities. I don’t have the exact figures to hand (though I presented them before on AB) but in recent years whenever the UK was opposed to a measure put before the EU Parliament the measure was passed nonetheless in around 90% of instances. So not only do you not have much influence over who represents you in the EU (and bear in mind MEPs in England, Scotland and Wales are elected by the "party list" (aka "jobs for the boys and girls") system). But once elected the UK’s MEPs are virtually powerless to prevent measures being passed that are not in the UK’s best interests unless they happen to be not in the best interests of a sizeble number of other nations too.
The majority of legislation that effects you (and your children and grandchildren since it's been mentioned) is drafted and proposed by unelected EU commisioners (MEPs cannot propose legislation themselves). It is passed in a forum where the UK has only ten percent of the voting power. If you are happy with that go right ahead and vote to remain. If that prospect disturbs you is only one alternative because no amount of "reform" will alter that basic principle.