Carema dropped and lens ring became loose

When I traveled last month, my camera (Panasonic GH4) with lens (Panasonic Lumix G Vario 14-140mm f/3.5-5.6) dropped from the bed to the floor. It was a stupid mistake; after that accident, I checked first, and didn't notice an obvious damage. But When I take pictures later, I found that the lens is not very responsive to my press.

I checked again, and found the connecting ring between the lens and my body has one side loose (see the picture). The lens has 3 small screws on the metal connecting ring that supposes to fix the metal with its base. But now one of three size is bulging up. I tried to screw the metal ring tighter, but it will stay.

I called Panasonic lens repair center in Texas and get a rough quote. The gave me a average repair for this type of problem: the repair + shipping will be half of the price of this lens in the current market. I can still take pictures from this lens. I just have to be aware that the loose side and use my left-hand to make it tight when I press the shutter. When it was hanging on my neck, I also feel like it may fall off (maybe it's psychological suspicion)

I have another lens 12-35mm( Panasonic Lumix G X Vario 12-35mm f/2.8) and am thinking to buy another one (probably Panasonic Lumix G X Vario 35-100mm f/2.8 ASPH. POWER O.I.S. Lens). If I plan to buy that one, do you recommend me to fix this one?

After that travel, I have not used that lens anymore What are the cons if I leave this lens loosely like this and continue to use it as it is OK? Humidity issue? dust? If you were me, will you repair it?