Ptotic salivary glands dropped: would botox or mini neck lift help? (photos)

i’m 24 and have loose neck and jaw skin. in the past year my salivary glands have dropped down and are enhancing my submental submental fullness. why does this happen since i’m so young? would botox help? i’m worried that by the time i’m 40 they’ll be down to my shoulders. i’m considering a mini neck lift because of how excessive the loose skin is, could the loose skin be pulling the glands down or vice versa and how do i prevent it from getting worse?