Localhost SQL server is tanked? Nuke everything

nuke.sql

USE master;
GO

SET NOCOUNT ON;

BEGIN TRY
    -- Instance cleanup
    DBCC FREEPROCCACHE WITH NO_INFOMSGS;
    DBCC DROPCLEANBUFFERS WITH NO_INFOMSGS;
    DBCC FREESYSTEMCACHE ('ALL') WITH NO_INFOMSGS;

    DECLARE @dbname sysname, @sql nvarchar(max)
    
    DECLARE db_cursor CURSOR LOCAL FAST_FORWARD FOR 
    SELECT name FROM sys.databases 
    WHERE state = 0 
    AND name NOT IN ('master', 'tempdb', 'model', 'msdb')
    
    OPEN db_cursor
    FETCH NEXT FROM db_cursor INTO @dbname
    
    WHILE @@FETCH_STATUS = 0
    BEGIN
        SET @sql = N'USE [' + @dbname + ']; 
            EXEC sp_MSforeachtable ''SET QUOTED_IDENTIFIER ON; UPDATE STATISTICS ? WITH FULLSCAN'';
            EXEC sp_MSforeachtable ''SET QUOTED_IDENTIFIER ON; ALTER INDEX ALL ON ? REBUILD WITH(ONLINE = OFF, SORT_IN_TEMPDB = ON)'';
            CHECKPOINT;'
        
        EXEC sp_executesql @sql
        
        FETCH NEXT FROM db_cursor INTO @dbname
    END
END TRY
BEGIN CATCH
    SELECT ERROR_MESSAGE() AS ErrorMessage;
END CATCH

IF CURSOR_STATUS('LOCAL','db_cursor') >= 0
BEGIN
    CLOSE db_cursor
    DEALLOCATE db_cursor
END