For the Halti, you just need persistence, patience and time I think. Keep associating it with treats and praise and good things, keep working with him every day with it. Don't ever get angry with him regarding it or he'll sense that and associate it with the Halti. If you feel you are losing patience, just stop for a bit and try again later. It will take time. Dogs dont' like feeling things on their face, it's totally natural for them to try to swipe it off.

It's hard to suggest foods for you because I'm not sure what is available to you and what you can afford. You mentioned Pro-Plan before and I think that would be better than Ol' Roy if you can afford the price increase.

Keep up the good work and keep trying. Puppies can really try your sanity at times. They take so much persistence and time. But it pays off 100-fold in the end.