The other comments are solid, and this is one of those questions whose answer probably won't help much in solving your problem (due to its nature, not for a lac

The other comments are solid, and this is one of those questions whose answer probably won't help much in solving your problem (due to its nature, not for a lack of good answers). However, I can offer you some time and insight if you want a technical person in the ML/NLP domain to bounce your ideas off of before you get too far into it. Contact information is on my profile, if you so wish.