What are your PC's specs: CPU/GPU/free space on C:\?
A reverse test here slowed export during the clip but the result had no freeze. Upload that file please, so someone can check it out. Use a free server, such as Google Drive or MS OneDrive, get a shared (public) link, copy the link and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum. Using Google Drive, if necessary change "restricted" to "anyone with link can view."
In the interim, click the + sign to the right of the Sequence 1 tab, to create a new blank Sequence 2. Drop the non-reversed clip from the BIN into that sequence. Reverse it. Export the sequence.
Now return to Sequence 1. Right-click the original reversed clip and choose REPLACE CLIP from the drop-down menu. Windows Explorer (the file manager) will open. Locate the clip that you just saved and double-click on it. Now you should find that export goes much faster, without a hitch.
At every step, Save Project File AS routinely, giving it a unique # or name, so as not to overwrite prior saves. Using Save Project Files (no AS) will overwrite. From the HOME tab, that choice is available by clicking the chevron to the right of the Save Project button on the toolbar.