Incorrectly counts the we have added a generator point to itself in a loop (SECP256K1, Python),

Question

I have a script that converts a bitcoin private key into x and y coordinate with parameters of a Secp256k1 curve. Here's the script:

a = 0
b = 7
#Order of the finite field
prime = 2**256 - 2**32 - 977
#G coordinates
gx = 0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
#Order of the group G
n = 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
#n -1 => is the number of all possible private keys

def addition(currentX, currentY, gx, gy, a, b, prime):
    if gy == 0:
        return (None, None)
    elif currentX is None and currentY is None:
        return (gx, gy)
    elif currentX == gx and currentY != gy:
        return (None, None)
    elif currentX == gx and currentY == gy and currentY == 0:
        return (None, None)
    elif currentX == gx and currentY == gy:
        s1 = (3 * pow(gx, 2, prime) + a) % prime
        s2 = (gy * 2) % prime
        s = (s1 * pow(s2, (prime - 2), prime)) % prime
        currentX = (s ** 2 - 2 * gx) % prime
        currentY = (s * (gx - currentX) - gy) % prime
    elif currentX != gx:
        s1 = (currentY - gy)
        s2 = (currentX - gx)
        s = (s1 * pow(s2, (prime - 2), prime)) % prime
        currentX = ((s ** 2) - gx - currentX) % prime
        currentY = ((s * (gx - currentX)) - gy) % prime

    return (currentX, currentY)

def secp256k1BinaryExpansion(privateKey, gx, gy, a, b, prime):
    if pow(gy, 2, prime) != (pow(gx, 3, prime) + a * gx + b) % prime:
        return "The point is not on the curve"
    counter = 0
    coef = privateKey
    currentX, currentY = gx, gy
    resultX, resultY = None, None
    while coef:
        if coef & 1:
            resultX, resultY = addition(resultX, resultY, currentX, currentY, a, b, prime)
            counter += 1
        currentX, currentY = addition(currentX, currentY, currentX, currentY, a, b, prime)
        counter <<= 1
        coef >>= 1
    print("Counter", hex(counter))
    return (resultX, resultY)

priv = 0x45300f2b990d332c0ee0efd69f2c21c323d0e2d20e7bfa7b1970bbf169174c82
xPub, yPub = secp256k1BinaryExpansion(priv, gx, gy, a, b, prime)

However I cannot correctly count how many addition there has been after the function is completed. By definition, there has to be

0x45300f2b990d332c0ee0efd69f2c21c323d0e2d20e7bfa7b1970bbf169174c82

additions (The same number as the private key). The counter variable in the function counts how many times the addition has been made. However the print("Counter", hex(counter)) outputs:

0x4132e8968fdd0e98de5fde704b470bc4c38434f96bf7077034ccb099d4f00ca2

Which is incorrect. How to fix that error?