So I play a level 10 bladesinger wizard in a campaign with 4 others. A cleric, Barbarian, a Ranger(multiclass with others), and the DM. Let me start off by saying that my dm runs some pretty deadly combat like 2 hits from just one enemy on average can drop my character. I’m not a power gamer at all but my character can max out his AC at 30(he has a dex of 16 int of 20). With mage armor, my bladesong, my bracers of defense and my favorite spell haste I can have a 25 ac then I can use my reaction to shield. Now in order to balance that I have the lowest hp in the party by 35 hit points plus mediocre saves(my highest is 9 to int saves then a 6 to wis saves). My dm wants to lower the amount of ac my blade song gives me by 2 and to also lower the added bonus to my concentration checks which is a 6 when my blade song is up(I have a 12 in con). He told me that because my ac was so high that I was the tankiest pc(even next to the maxed out con Goliath totem Barbarian with the tough feat). I totally understand if it’s a balancing issue but when our combat is so deadly that one pc can go down at least twice(we also use a rule that if you come back up from unconscious you have a level of exhaustion). I feel like this is coming out of nowhere when he has almost killed my character once and brings me to single digits every combat despite my ac. Am I being a brat about this because i will totally admit if I am but idk this just feels weird?

Edit:Thank you all for all the responses, advice, and criticism. I gotta just want to say that my character is not the only one built with a specific goal in mind. Our barbarian and ranger are way more optimized for combat. We spoke briefly but neither of us had the time to sit and discuss. I plan to talk to him with some more and bring up the talking points you guys brought up here, and if he still wants to nerf my character I may just bring in a new one or just bow out for the rest of the story. Which both options I’m not the biggest fan of as this was my first wizard and the whole reason I played one was the thought of a melee wizard since I love martial classes. I don’t think he’s a bad dm and he also mentioned that I wasn’t the only bladesinger hes dming for. He just thinks out high ac is op as the other guy has a similar ac(he has a higher dex than me but my bracers give me 1 point higher than his). I really love this campaign and have fallen in love with casters so thank you all for giving me the advice and tools to potentially stay in the game I’m in love with. I’ll update you guys if anything again!

Edit 2: I’ve been reading through all of your comments and just want to clear some things up. I have 55hp which is 35hp less than our cleric at 90hp. I am far from the most optimized class I didn’t mention it before because it’s a lot but our ranger is a multiclass(ranger/warlock/cleric) who uses a revolver and sharpshooter to deal insane amounts of damage. Our combats are pretty deadly but fun. Yes if I get hit in 2-3 hits I’m already looking bad. We fight cultist that deal about 13-17 damage. 2 hits and I’m pretty rough not to mention a crit, But that’s not the case for everyone else. Our Barbarian has saved us plenty of times with his high health and damage(special weapon that lets him crit on an 18 or higher.) Sorry for the confusion please let me know if anything else needs clarification.