You should feel like you are melting into the ground. You can practice for a lifetime but if your stance is poor you will have wasted all of your effort. If you meet the right Wing Chun guy, you will be in big trouble. Don't act before you know what is going on. You must feel what is happening first.
People act before they feel.
Random flurries won't work. You can't just rely on speed. The head should not be forward. Keep the head back or it will get hit and it also brings the whole posture down to stiffen up the hands. Keep the head up and rely on your touch.