My instance i-0f7bc795a0bc1bede in eu-west-1 region is unresponsive

Here are some steps to troubleshoot the issue you are having.

1. Create a new instance (NI) that you can login to in the same AZ as the broken instance (BI).
2. Stop BI
3. Detach root volume from BI and attach to the NI
4. Mount the BI root volume at the OS level on the NI
5. Examine logs, etc to troubleshoot what is going on. Fix.
6. Detach BI root volume from NI
7. Attach root volume to BI and start.