problems with infinite world generation, i appriciate every answer :)

Question

Hi!
i've got a little problem on my world generation: i want to make it infinite.

the terrain: https://ibb.co/4F7Pswv

the end of the terrain: https://ibb.co/nLQd1Xq (ignore the water in this one)

my code:

extends Spatial

var rng = RandomNumberGenerator.new()



    #################world generation##################################

    func _ready():
        #generating random number for seed
        rng.randomize()
        var number = rng.randf_range(1, 1500.0)
        print(number)

        var plane_mesh = PlaneMesh.new()


        var noise = OpenSimplexNoise.new()
        noise.seed = number

        noise.period = 185
        noise.octaves = 8


        plane_mesh.size = Vector2(900,900)
        plane_mesh.subdivide_depth = 450
        plane_mesh.subdivide_width = 450

        var surface_tool = SurfaceTool.new()
        surface_tool.create_from(plane_mesh, 0)

        var array_plane = surface_tool.commit()

        var datatool = MeshDataTool.new()

        datatool.create_from_surface(array_plane, 0)

        for i in range(datatool.get_vertex_count()):
            var vertex = datatool.get_vertex(i)
            vertex.y = noise.get_noise_3d(vertex.x, vertex.y, vertex.z) * 60

            datatool.set_vertex(i, vertex)

        for i in range(array_plane.get_surface_count()):
            array_plane.surface_remove(i)

        datatool.commit_to_surface(array_plane)
        surface_tool.begin(Mesh.PRIMITIVE_TRIANGLES)
        surface_tool.create_from(array_plane, 0)
        surface_tool.generate_normals()

        var mesh_instance = MeshInstance.new()
        mesh_instance.mesh = surface_tool.commit()  
        mesh_instance.set_surface_material(0, load("res://terrain_material.tres"))

        mesh_instance.create_trimesh_collision()

        add_child(mesh_instance)

(the pictures dont show all of the world)

if someone has an idea for infinite world generation (that doesnt destroy my pc) based on this code, i would like to hear it :)

thanks already