No! Probably only need to replace the "Potentiometer Sensor" link example click me

Looking at the link you can see the small White disk Sensors. You have those in each Stick on both Sides. Left one is your Up and down and the right Sensor dictates your "Left / Right" movement. Those Sensors do all the work. It's the most common issue in Controllers and even in old ones. It's rare that you'd have to replace the whole thing just because of this issue. Can always be a possibility tho

You can buy these Sensors cheap in bul on Ebay. Judging by your problem which is "Up" when moving the right Stick means you have to replace the left Sensor in your right Stick.

Just need a Screwdriver and calm fingers. You can easily break something as always with Tech lol. When taken the Controller apart you have to open the Side thingy at the Stick to expose the Sensor for you to change it, bending that too much, too hasty or with too much force causes it to break and then it's game over.

Too long didn't read; Buy potentiometer sensors for cheap. Receive it, open controller, be careful, change sensors and it should be like new. Or clean the old Sensor with alcohol sometimes that already works wonders because of dust and dirt etc