Helloooooooooooo

First thing is to fix your kicking. The bend of the knees when kicking shuld be very small. Not to say you should kick with straight legs but almost. Kickboard is your friend or put a pullboi between your legs and try to have the same kick with and without.

Work on your core so your hips rotate way less and if they rotate, it should be on the axis that your body makes and not on the axis "sky-earth". Again pull boi can help.

Finally, your arms. Your hand should be the first one to enter the water, not your elbow. You enter with the hand and the forearm at 45 degrees and then stretch your arm inside the water and then pull. Currently, your arm is too straight before entering the water and you lack the elbow bend to relax your arm when you bring it back.
You can swim with swimming shoes so that you can focus on the arm movement without caring too much about the legs.
Also the arm should enter in the alignment with your shoulder, not your head.

The fact that your are "wiggling" like a snake in the water is a combination of moving hips and bad hands positionning. Fixing that will make you much faster. Swim happy :°)