An easy way to find your mix is when you moan. Yes, really exaggerate that whiny moan. Notice this makes you sing less loud……….that’s a good thing.
Can you get through your bridge now? Did it make those high notes feel easier? It should because you are tilting your thyroid cartilage.
If it’s not helping much, then take the volume even lower and engage the muscles in the upper part of your abdomen. Do not flip into falcetto. Control that feeling without tensing your throat……….voila, MIX!!