17GB project. Too much.
General suggestions...
It appears that four files have been duplicated and loaded. Don't load any files that are not in the project. Eliminate duplicates. For example, untitled 54 is in the bin twice. A single file can be used in different sequences. Consolidate tracks - use as few as possible.
Consider pre-converting source files to lower resolution, perhaps trimming off parts that are not included in the project. If there's need to use different segments of a clip, right-click it in the bin and COPY. Then click an open bin area and PASTE (clip). Content for each dupe can be specified with the SET START & END buttons, while not affecting the other copies.
Unless there's a reason to do otherwise, suggest working with one sequence at a time, saving each as an individual project. If necessary, divide a sequence into smaller segments, exporting each, then merging those exports into a final export. (Your Sequence 2, mostly silent, appears to serve no purpose??) Sequence 3 has an overrun in black, which extends from the 1:56 end of content to nearly four hours. This can be fixed with a right-click in the area following the sequence. CLOSE GAP.
Also consider converting WAV files to mp3 prior to importing.
After those changes were made in Windows 10, converting video files to 854x480 - which eliminated 10GB from the project - Sequences 1 and 3 played on the timeline and exported okay - even at HD720 - but for a freeze near the end.