Sorry but - arrrgghhhh I forgot about this when getting a new pup (sorry my new one arrives this week)
It took my lot a good two months to settle with each other (guys who know me, i am talking about jock getting used to having Fern around) when we got Braan tho it took max of 2 weeks - so every dog is different as with humans
Yes you are doing right in keeping them seperate for food etc all contact should be supervised until they have settled in together, so the fact that you can crate the new pup is great
it'll take time but take baby steps and you will get there, I used to take pup out in the garden and tire her out and put her in the crate and then take the other dog for a nice long walk, then come back and take the pup out to the shops etc (carrying) to socialise her which gave the other dog space at home alone
Good luck and let us know how you get on
oooo welcome to COL