Hit the bag like it's a person. Bags don't hit back. So fight it as if you're fighting someone.
Do you really stand so close to your opponent? Your jab is not even extended fully.
So to make it more realistic. I want you to stand further back. Throw whatever from there. Jab or whatever but make sure you're connecting at the end of your jab. Meaning fully extended and barely touching the bag. This is the outside, learn your range. Fight on the outside for a bit.
Then Jab your way in. Once you're on the inside, they can hit back so you better work. Body, head, hooks, uppercuts, everything. Don't stop in the middle, keep your guard up. Work, then bounce back to the outside SAFELY. Safely meaning in a way that they can't hit you back; so either pushing them before bouncing back or at the end a combo and strafing backwards, etc. Then continue to pick your shots from the OUTSIDE.
I only skimmed through the vids but I'd like to see some defense. Move around, don't stand in the same spot. You don't fight standing still, so don't work the bag standing still. Move left to right, right to left. In and out. Keep your guard up, shadow defend while picking shots. Jab, slip, counter hook.
Working the bag is same as shadow boxing but with an actual target to hit. Bag work is not good for beginners because it creates bad habits. Shadowbox in front of a mirror first working on both offense and defense. Then use those on the bag.