HELP--export options make my project unusable

hi, i need help asap. i have a 16 min piece that uses primarily photos, but also short video clips, music and VO. im documenting boys who have been bonded into slave labor on fishing boats in southeast asia. i need to post asap to several human rights sites and after working very hard for 2 weeks the piece is unwatchable bc the quality after exporting is so poor. in fact, the 48 pt font subtitles are unreadable to say nothing of the image quality, which is SO MUCH WORSE than i ever imagined. i used the mp4 option bc the other options seemed inappropriate for web posting to others’ sites. please please help. im so upset with this. thank you.