HELP! Flat nipples🙄hard time breastfeeding

I’m pregnant with my 2nd little man and want to be able to breastfeed longer this time. I’m due October 27th and have been looking online for different things to help but there are so many different options. When I was at the hospital and they were trying to help they had me using a shield and it helped but still really hurt a lot and never got better. We both just got aggravated and cried most of the time while feeding because he couldn’t latch and I just felt like a failure because I didn’t know what else to do even after seeing a specialist. Any time I would see the nurse or specialist they told me he was doing great but any other time he would scream 😫 So I only ended up breastfeeding him for maybe 2 months. I’ve looked online and have found breastfeeding shells for flat or inverted nipples and little contraptions you can use to make them come out but I have no idea what to get. Can someone who has had this issue give me any advise on what worked or what to get? I feel like if I can get this figured out this time I’ll be able to do it I had plenty of milk and it came in the 1st full day at the hospital after I had him the nurses were so surprised it came in so quick but it just didn’t work out and I really want it to this time. Thanks!😊