next(iterable) works but 'for' loops just creates an infinite loop

I'm trying to recursively iterate through all my nodes, however I get an infinite loop.

class Dictionary:


  class Node:

    def __init__(self, key, value):
        self.key = key
        self.value = value
        self.nextNode = None


    def insert(self, key, value):
        if self.nextNode is None or key < self xss=removed xss=removed xss=removed class="hljs-keyword">elif key > self.nextNode.key:
            self.nextNode.insert(key, value)
        else:
            pass

    def __iter__(self):
        if self.nextNode is None:
            return self
        else:
            return self.__next__().__iter__()



    def __next__(self):
        return self.nextNode


    def __str__(self):
        return f'{self.key} : {self.value}'

def __init__(self):
    self.__head = None


def insert(self, key, value):
    if self.__head is None or key < self xss=removed xss=removed xss=removed class="hljs-keyword">elif key > self.__head.key:
        self.__head.insert(key, value)
    else:
        pass



def __iter__(self):
    return self.__head


def __str__(self):
    return str(self.__head)

d = Dictionary()
d.insert(2, 2)
d.insert(3, 3)
d.insert(4, 4)
d.insert(5, 5)

When I do:

p = iter(d)
print(p)
print(next(p))
print(next(next(p))

it works, but when I do

for i in p:
    print(i)

I get an infinite loop that prints 3s. It doesn't even jump nodes.

Isn't a for loop just the same thing as doing iter() and then using next() a bunch of times until I hit a condition (None)? Shouldn't I be getting the same thing for these? What am I doing wrong?