It can be very hard at first, you're not alone there. And I remember dreading feeding with DS too.
I urge you to find a good LC in your area - you can post here to ask or PM Barb Glare or even call the ABA for a rec - and get that tongue tie looked at. She may also be able to give you some more advice about the attachment - it's always worthwhile getting a 2nd or even 3rd opinion.
It really, really does get easier! But you may need some help in the mean time. Try to remember that she's only very little and getting used to being on the outside. She will want to be held all the time regardless of how youfeed her - it's just how babies are. Being able to breastfeed when they're fussy and needy can actually make things much easier for mums.