Start with your bike fit. You have a road bike, ie, not TT.
Bike geometry begins with getting about 60% of your body through the rear wheel. So, getting your butt in the right place is the best place to begin. The saddle top should be parallel with the ground, ie, not tipped up, (which yours looks it it might be), neither down.
There are many fancy ways of getting the leg length right, but the old way is still relatively accurate:
with your bike in a doorway, you can balance the bike with your hands on the door frame, with your cycling shoes on, and your heal, not toes, on the pedal extend the pedal so that it is in line with the seat tube, you should just lock your knee out of your shorter leg, so back pedal and test each leg, and raise/lower the saddle accordingly.
Next adjust fore and after, in your case this is possibly the cause. With your cranks horizontal, ie, 3 and 9 oclock, and your feet in the pedals, the front of your knee, the big tendon, should be directly over the pedal spindle., adjust fore and aft of the saddle, by undoing the saddle bolt and sliding the saddle alng its ‘rails’, when you tighten them, make sure the saddle is still parallel with the ground, now recheck the leg length, in most cases that will be ok.
In this position, your weight should keep you butt in the right place, and reduce the tendency to slide forwards or back.
Now think about your bars position, height and length, they are much more about comfort. Your arms should have a slight bend when on the hoods, ie, flex in your elbows, never locked out.
In this position you now reduce the direct weight on the bars, as your body weight is spread about the saddle, pedals and bars.
This is a good starting point. Fine tune these adjustments. With leg length if your hips rock side to side as you pedal, the saddle is a little too high, ie, you are having to stretch your legs to maintain pedal contact.
Give this a go.