Please help! What will tighten my neck or get rid of these lines? (Photos)

You're right. This is a difficult problem and the solution is not in sight. However, some patients have been happy with fractional non ablative erbium laser Palomar Lux 1540. This puts micro columns of coagulated tissue into the skin, with each pulse. These micro thermal zones then have to be extruded over the next week, and new collagen fills in and the skin looks better. I recommend the larger 15 mm array which is gentler and more superficial than the more powerful 10 mm lens that is used for stretch marks and scars.
You can also use micro botox, which has been known for over 20 years, with many publications, such as those by Dr Wu, in Singapore. Tiny injections of 25-30 units of botox just into the dermis, not the muscle, by some mechanism, such as relaxing the smooth muscle attached to the dermis, seems to smooth out the skin. It is used also to treat hypertrophic scars. But the effect may be temporary, like Botox, and needs repeated treatment at intervals, like Botox.
I have tried Renuva under the lines, but it did not work, so currently recommending trial of the 15 mm Palomar Lux 1540 non-ablative erbium laser.

Morpheus 8 is a non-invasive skin and soft tissue tightening treatment that is consistently amazing in our patients. We use the Morpheus to exact fractional induced RF into the skin or tissue in order to tighten collagen and stimulate contraction of the tissue. For acne scars, it is quite useful to build collagen in patients who have atrophic scars but is not very productive for ice-pick scars which require TCA Cross. For tissue tightening, Morpheus is ideal for the face and neck and we often combine it with CO2 laser or Ultherapy to further enhance results. Chemical peels and skin resurfacing should be done at least 5 to 7 days after, but can be performed earlier, depending on treatment severity. Avoid exfoliating skin treatments before Morpheus and expect a period of 2-4 weeks for skin contraction to set in.

Best,
Dr. Karamanoukian
Realself100 Surgeon

Morpheus8 is an option to improve the appearance of the neck lines that bother you. This treatment uses RF technology combined with microneedling to improve overall skin tone and texture. Typically three treatment sessions are recommended for optimal results. You can learn more by visiting my website or a provider near you.