C# direct3d draw sprite eats up money and throws exception

Question

I have a problem here with my C# application. It should be a DirectX / D3D Game overlay to show me current song I hear on Spotify. This is the drawing code:

private void dxThread()
    {
        while (!_StopThread)
        {
            #region DeviceWork
            device.Clear(ClearFlags.Target, Color.FromArgb(0, 0, 0, 0), 1.0f, 0);
            device.RenderState.ZBufferEnable = false;
            device.RenderState.Lighting = false;
            device.RenderState.CullMode = Cull.None;
            device.Transform.Projection = Matrix.OrthoOffCenterLH(0, this.Width, this.Height, 0, 0, 1);
            device.BeginScene();
            #endregion

            #region Drawing
            IntPtr handle = FindWindow(null, WindowName);
            if (handle != IntPtr.Zero)
            {
                RECT wrect = GetWindowRect(handle);

                switch (OverlayCustomizer.bg_source)
                {
                    case 0: //Default
                        DrawPicture(wrect.Left, wrect.Top, SpotifyOverlay.Properties.Resources.Default_Background, OverlayCustomizer.bg_tint);


                        break;
                    case 1: //Simple color
                        FillRect(wrect.Left, wrect.Top, OverlayCustomizer.size_x, OverlayCustomizer.size_y, OverlayCustomizer.bg_simple_color);
                        break;
                    case 2: //Custom

                        break;
                    default:
                        break;
                }

            }
            #endregion

            device.EndScene();
            device.Present();
        }
        this.device.Dispose();
        ThreadOver = true;
    }

So it accesses there a DrawPicture function which I made here:

    public void DrawPicture(float x, float y, Bitmap bitmap, Color tint)
    {
        Texture texture;
        Rectangle textureSize;
        texture = new Texture(device, bitmap, Usage.None, Pool.Managed);
        using (Surface surface = texture.GetSurfaceLevel(0))
        {
            SurfaceDescription sd = surface.Description;
            textureSize = new Rectangle(0, 0, sd.Width, sd.Height);
        }
        Sprite sprite = new Sprite(device);
        sprite.Begin(SpriteFlags.None);
        sprite.Draw(texture, textureSize, new Vector3(0, 0, 0), new Vector3(x, y, 0), tint);
        sprite.End();
    }

But after 30 seconds the application crashes with following exception:

An exception (first Chance) of type "Microsoft.DirectX.Direct3D.Direct3DXException" in Microsoft.DirectX.Direct3DX.dll was trown.

Sorry for my english but the error message is german like me :) When I look in the Task Manager it says my Application gains memory till it reaches 1GB of RAM and then it crashes. Anything to draw that sprite better? Thanks!