Can you describe in what way you think of Kurt as independent in the first few seasons? And why you think he wasn’t in later?
Sure thing. In earlier seasons he has his own goals and motivations and he believed in himself. Whilst, towards the end of the show he basically only existed as Rachel's friend and Blaine's husband.
He went from "one day you will all work for me" to going all the way to Lima to cry to Rachel about losing Blaine after HE was the one to break it off because he wasn't happy in the relationship. He then proceeded to spend the rest of (or at least from what I've seen of) season 6 only caring about getting back with/getting over Blaine. That's it. He's completely lost his independent motivations and has become a supporting character in his own life.
Season 1 Kurt was an independent man who believed wholeheartedly that he would get out of Lima and make something of himself. He had ambitions and he had the motivation and confidence to achieve those ambitions regardless of what the world thought of him.
Season 2 Kurt was repeatedly being pushed to change who he is to fit in with his peers (a pressure put on him by bullies, his "friends", and Blaine). But, he eventually decides to say fuck it and be himself and realises that he shouldn't need to change for the world.
Season 3 Kurt is still striving for something (getting out of Lima) and being pushed down at every turn (not getting the lead role in WSS, not winning the election, not getting into NYADA). This is when he starts to lose belief in himself but he still never gives up.
Season 4 Kurt starts by staying in the town he's been trying to get out of his entire life for a guy. Having begun to give up. But, once he leaves (and they break up) he does get to explore, get a job, get at least one new friend, and figure out who he is on his own terms. All of which is promptly thrown aside in favour of getting him back with his ex.
Season 5 Kurt still has some agency but exists mostly to back up and support Blaine and Rachel, having almost completely given up on his own dreams and ambitions.
Season 6 Kurt literally has no ambition outside of Blaine. He is now completely and utterly dependent on another human being. One which he himself admits makes him feel bad. The show then ends with Blaine being a famous actor (something it was never really clear he wanted, but which was Kurts dream) and Kurt being... well... Blaine's husband.