my ec2 instance has vanished

When an EC2 instance appears to have vanished, it can be concerning, but there are several steps you can take to investigate and potentially recover your instance:

1. Check the correct AWS region: Ensure you're looking in the right region where your instance was originally launched. Sometimes instances may appear to be missing if you're viewing the wrong region.

2. Use EC2 Global View: This tool allows you to see all your EC2 resources across all regions, which can help locate your instance if it somehow moved to a different region.

3. Check CloudTrail logs: Look for any "TerminateInstances" or "DeleteInstance" events in CloudTrail. This can provide information on when and why the instance was removed.

4. Verify instance state: Your instance might be in a "stopped" state rather than terminated. Check for stopped instances in the EC2 dashboard.

5. Look for EBS volumes and snapshots: If your instance had attached EBS storage, check the EBS dashboard for any remaining volumes or snapshots. You might be able to recover data from these.

6. Contact AWS Support: If you can't locate your instance or determine what happened, reach out to AWS Support for assistance. They may be able to provide more information or help with recovery options.

Regarding exceeding the free tier limits, it's important to note that this doesn't automatically cause your instances to be terminated or disappear. However, you may start incurring charges for usage beyond the free tier limits.

For future reference, to avoid similar situations:

1. Set up AWS Budgets or Free Tier usage alerts to notify you when you're approaching your limits.

2. Regularly monitor your usage through the AWS Billing Dashboard.

3. Be aware of the Free Tier limits and terminate (not just stop) instances you're not using.

4. Implement proper access controls and deletion protection for critical resources.

If you're unable to locate your instance after these steps, it's possible that it may have been unintentionally terminated during the process of creating and deleting the image. In this case, you may need to rely on any backups or snapshots you have to recover your data.
Sources
EC2 Instance has disappeared | AWS re:Post
AWS EC2 Free Tier Usage Reached 100%, Unable to Connect to Instances - How to Manage the Situation | AWS re:Post

I even tried to recreate a new instance, but the t2.micro is no longer available. Is this because I exceeded the free tier usage

Sounds like you may be in a Different region than where you started. Can you confirm which region you are in and where you created the EC2?

The region was us-east-1, but no instances appear, not even in the global dashboard