I was just about to suggest that you try silver cups but it sounds like you’ve exhausted the menu of options. I’ve heard that applying cool cabbage leaves on breasts can help relieve pain and engorgement but I haven’t tried it myself. I went through something similar and silver cups helped but to be brutally honest - I ended up just putting up with pain for a little and then it did not hurt anymore. Not suggesting you should do the same because the degree of irritation is different for different people. Perhaps try cabbage leaves. People say it does wonders. That’s assuming your baby is latching on properly.
I'm 11 weeks postpartum now and I had extremely painful nipples for the first 6 weeks, honestly it was awful and made me dread each time it came to feeding and it was much worse on one side than the other. I would carry on with the nipple cream and don't be shy with it, put it on every hour and after every feed as your nipples will get worse if they are able to dry out and scab over. I would also advise speaking to your midwife or a feeding specialist as my baby just didn't have a good latch for a long time and it turned out she had a slight oral restriction so I was given some oral exercises to do with her and lots of help getting positioned better to get a better latch, it took a while but my nipples have recovered and they're no longer constantly painful!
I found olive oil helped me personally. I tried all sorts but found this the easiest to apply without it hurting and it provided me more relief than nipple creams.
Cucumber, whack it in the freezer and get it in your bra when you’re not feeding!! Same with cabbage leaves random but it works! They will just crack due to you starting to breastfeed and them adjusting to being used to feed. I found no amount of nipple cream helped just when not feeding not wearing a bra for a little bit, warm bath or shower and then the cucumber or cabbage leaves! It gets better honestly!