haq ((unmumsnetty hug))
Yes it definitely gets easier. The tongue tie makes it very hard on your nipples. As he grows and learns to feed more efficiently it gets better.
Cluster feeding is a tough one as everyone says just go with it to increase your supply. But then the midwives would tell me to limit feeding to 30 mins max each side every 2-3 hours to save my nipples (I was never really able to do that- I would always end up feeding on demand). So you get all this conflicting info. It's hard at the start.
The other issue is that the tongue tie might be making it difficult for your baby to take milk from the breast, hence the long feelings. If you feel that feeding is non-stop and that your nipples are very bad I would consider re-visiting the tongue tie issue.
For me, my nipples were bleeding from day 1 with DS2 and when he would spit up there was blood in it 
I also had to give a formula top-up for the first few days as he had had urates (I think it's called) in his nappy- i.e. he was getting dehydrated. We are now down to about 3-4oz formula per day and hoping to get rid of it completely over the next few days.
So keep an eye on the nappies as if your baby is having lots of wet and dirty nappies then he is obviously getting milk from the breast and the TT is not a major issue.
Wrt your nipples, try Multi-Mam compresses, pricey but a lifesaver IMO.
Keep going, this bit is tough but it is not for long 