I see this question is nearly a year old now, forgive me for reviving this, but in case you're still looking, (or for others who wander here on the same quest).

I suggest checking out [Affinity Photo][1].

For vector work, [Affinity Designer][2] is also pretty good and acts as a direct competitor to Adobe Illustrator. It's amazing how easy it is to work on the same file in both suites, it feels seamless, like you're just changing the workspace.


  [1]: https://affinity.serif.com/en-gb/photo/
  [2]: https://affinity.serif.com/en-us/designer/