discouraged and emotional. I wanna give up

My son is now 5 weeks old, I've been breastfeeding him since day 1. The first week was absolutely horrendous. It felt like a piranha was at my nipples 24-7. It's now better! Thank god. My right nipple how ever is cracked pretty bad and still is tender when he latches on at first and hurts. Once he starts sucking, the pain goes away for a little but then returns once he's finished feeding. It's pink on the nipple and has pain but isn't shiny or scaly. What is good for cracked nipples?? Onto my next issue...... my son is super f**king fussy on the boob! Pulls off, crys, latches back on, crys, repeat repeat... now I get this May be an overactive letdown- I haven't felt anything but I've read symptoms and it sounds like that's what it is. I still don't know how to fix that & is driving me and my son insane. While out shopping, driving in the car, getting groceries - and he starts crying due to being hungry.... HOW TF CAN I BREASTFEED IN PUBLIC GROCARY SHOPPING...not happening . My anxiety level then rises so high,.. I rush to the car and sit in there and breastfeed..I'm also low on sleep due to me being the only one up with him in the middle of the night. For hours on end... IM SICK OF IT. I have no sleep, my bf doesn't do shit but change his diaper occasionally, like I feel like I'm the only one doing anything!! I get breastfeeding has its benefits and half of me doesn't wanna give up but the other half - it's taking its toll on me this whole breastfeeding thing. I find myself crying because of the stress it puts on me through out the day , out and about on errands, at night with no sleep... I just don't know what yet hell to do ... it's extremely depressing for me .. 😢and as we speak , my son keeps being fussy on the boob, is hungry but won't effing eat!!!!!!!! I've tried everything and I just wanna sleep 😩😩😩😩😩😩