Dm and party treats me like a damage sponge, what should I do?

Hello everyone! I'm new here but this has seriously been bothering me and I wanted to get some other opinions on this.

This is my second time playing dnd (third if Bg3 counts) and in this campaign I'm a barbarian, the others in the party are a Warlock, Rouge, Paladin, and Monk.

Were nearing the end of the campaign and its been bugging me like crazy that the party and the dm kinda just treat me like a damage sponge and care nothing for my backstory or roleplay moments. My backstory is simple, I worked as a knight in a prosperous city and was married to a half-ork, but Mindflayers invaded and destroyed the town and stole my husband from me, so now I'm using my husband's axe (his weapon of choice) as I search the world for him, using my rage and desire for vengeance to strengthen the axe.

Now this seems fine and all but every session I have to remind the dm of this as he keeps "forgetting" my backstory or just brushing it aside even though its readily available to him in the group chat. Not only this but every session we've had has been about either the warlock, rouge, or paladin and they have had seriously epic sessions. The warlock has had every session surrounding him and his patron as we search for his patron's cat eye orbs, the paladin has had two sessions both with epic boss fights, and the rouge has had two sessions and gotten tons of guidance and divine intervention from his goddess. Yet all I've gotten was half a session where we saved my pet gelatinous cube with a seriously lame boss fight that ended in one turn, and of course the first half of the session was just the warlock flirting with his patron and every girl he ever finds.

Another issue is that every combat I'm the one up-front dealing damage, tanking damage, and usually the one killing stuff, yet the warlock and rouge go around taking the heads of what I've killed and showing them off to npcs. Now this wouldn't bother me if it wasn't for the fact that they always say "I'm not your average adventurer" or "Look what I've killed" when its something they stood in the back and watched me kill. It wouldn't bother me nearly as much if they'd just say WE instead of ME or I all the time. It doesn't help that every time I've tried to speak up or do some roleplay it quickly gets rushed through or the warlock steps in and does it all himself.

It doesn't just stop there though, the warlock has gotten multiple homebrew feats, buffs from his patron, inspiration every session, power from the orbs we've collected, and gloves that buff his spells a lot. The Rouge has gotten a super powerful bow, blessings from his goddess, and spider robes. The paladin got blessings from his god Tyr, a shield that let him cast magic and gave him an AC of 22, and an infinite supply of javelins he can use divine smite with. And of course following all this I should have gotten some cool stuff right? All I have is a ring of water breathing and my pet gelatinous cube in an amulet... and it also bugs me that every time I buy stuff from a store or something the party just helps themselves to it, last session I spent 400 gold on healing potions and they all just snatched them from me and didn't let me have any of them, not even the lesser potions.

All this combined has been wearing on me like crazy and making me feel like the party doesn't care about me at all even through (last boss fight with a froghemoth proves) if I'm not there to tank for them they all die very quickly. For context the froghemoth went up and attacked the people who always sit in the back (rouge and warlock) and they absolutely got swallowed super quickly, only after I got up to deal damage were they able to escape and do what they needed to do. But it also really bothers me that from info I've gotten the mindflayers are in this forest were in currently so that's where they have my husband, I really wanted to go do something with it but before I could say anything the dm forced a plane shift on us and now I'll never be able to find him and now there's no reason for my character to keep up with the group.

I know its alot and I'm sorry if its way too much reading but I'm seriously losing it with this group, all they do is flirt and bang everything they see, ignore anything I say, and then take credit for anything I did. What should I do? Were down to the last two or three sessions of this campaign and I'm really considering just giving up but I also don't want them to die right at the end of their arcs. Any advice would be appreciated.