I think I'll have to have a few more trys at this, and perhaps the
club will let me help out a bit with some of the unskilled work so I
can watch and pick up things gradually.

It sounds like you are on the right track if you want to do this. Many pilots have initial issues with airsickness and/or low g sensitivity early in their training. As was pointed out, some never overcome it and wisely drop out.

Otherwise, it often helps to make several flights in cool smooth morning or evening air and then build up to the bumps or gentle pull ups and push overs as you gain exposure and get "bored" with the smooth stuff.

Many students make this transition rather quickly in a few flights and to on to really enjoy soaring.

Also, as you mention, finding a way to hang around the airport helps build confidence. Seeing folks having fun and coming back with no harm seems to have an effect on most people with concerns.