I installed 800 sq ft of 8mm laminate flooring over concrete, with 40 linear ft of laminate T-molding installed in a track. The T-molding transitions between the existing Marble floor and new laminate. In many areas the T has broken/separated and is stuck inside the track while the top of the molding is totally loose. From what I have read on this helpful forum, it happened because the marble tile is anywhere from 1/8 to 1/4" higher than the laminate floor and should have been perfectly level? Should I try replacing with hardwood oak T molding and try to plane or shim in some spots along side the 'T' to level it? I also thought of trying to find a Schulter type metal transition which laps over the laminate and then cutting a marble decorative edging for the other side of the metal to meet the marble tiles, but I do not know which type of metal transition would allow the laminate to still float. I am definitely in over my head here (retired, widowed) and I have not found anyone willing to come out to correct my mess. Not that I would blame em... Any advice is deeply appreciated! Thank you!!

The best solution would be to buy new T-molding and glue a shim under the part that has the gap. Use a wood color that matches the molding as well as possible, then glue with Titebond II using spring clamps. You would need to get the wood shim material and rip it on a table saw. The small edge visible under the molding should not be a distraction. Sorry your installer did not plan adequately.
Trying to use the broken T-mold would not be productive, but could be done as a last resort.
Pop the old pieces out of the track with a screwdriver being careful to not wrack the fasteners.