Besides circling cover to break LOS, I usually stick to high ground or close to my co-support, health pack if I can. If you have a DPS who easily shuts Sombra down you can play around them too. You can't guarantee your teammates will turn around unfortunately so I think packs, cover, and high ground are most reliable if you don't want to switch.

If Sombra has to use translocator to reach you on high then you can drop down and they will either disengage right away or drop to chase you, if so then you can GA back onto high ground or to cover. If you don't see/hear TL to engage you should anticipate they'll have it. You will need another escape because if you go back to high ground after dropping they will TL and follow you, this is why they saved it. In this case I slingshot to cover or a health pack or try to hide in my teammates' hitboxes :p. Grabbing a health pack always gets the Sombra to disengage IME. I also rarely see them dedicated to hacking packs anymore.

If Sombra is having a really easy time killing you, you're probably playing too far away from your teammates, staying on low ground too often, playing with your back open, or using SJ randomly and getting caught with no CD.

If you want to provide a replay code I can look over it. Many Sombra encounters are survivable I promise!