Hi there Doch777,
Thanks for contacting us. We know it’s important to listen to music and content with the Spotify app, and we’re happy to assist.
You’ve done some great steps so far. Please try the other steps listed here: If an app unexpectedly quits, stops responding, or won’t open
Can you use your other apps without any issue?
On your iPhone go to Settings > General > iPhone Storage. Check for the amount of storage available on your iPhone. Having storage on your iPhone can help fix performance issues. Try to maintain at least 1 GB of free space. Use the steps here to help with this process: How to check the storage on your iPhone, iPad, and iPod touch
If you have other questions, please let us know.
Stay safe!