Most dogs do not like to have their nails trimmed and it takes a bit of training to get them used to it. Sometime treating the dog with human food by one person while the other person trims the nails is all it takes , or putting the dog on a table as if her were to get groom he is more likely not to struggle. also doing one nail a night can help the dog get used to having his nails cut, try to sneak up on him when he is already sleeping and give a fast clip of one nail. Another option is just to bring the dog to the vet and having a vet tech do it. It is not as costly as a regular visit but may range from 7 to 10 dollars.
It is doubtful that a vet will prescribe meds to do this because of possible side effects. Over the counter melatonin has been known to help with anxiety and I will direct you to a site on this. Benadryl can make a dog sleepy so that may help as well.
If you are using nail clippers you may want to think about using a dremel or the new pedipaws that has come out on the market. They are being sold all over so it does not have to be ordered online. here's a site to show you how to use a dremel .
Could you tell me how far down to clip or file the nails? Are there any tips or tricks to identify the point you can trim to?
I would not use them both together. Melatonin can be purchased at a drug or health food store as can benadryl. Use benadryl allergy and not the allergy/sinus.
You can try one product one day and the other product the next day and see which results you like better.
You have to be careful of hitting the quick, so if the nails are long then there is probably a long quick so just take off the area that curls over. In some cases if the nails are white you can actually see the quick inside the nail. If you should cut it too short and the nail bleeds you can stop the bleeding with Quick stop. (styptic ) , if you don't have that you can also use flour, just put the flour in a small cap then dip the nail into it. Here's a site that will show you on video where to cut the nail.