Re beef tongue:- Cut off the stringier parts and the tip of the tongue and throw them away for now. The pinkish-reddish slab-like meat in the beef tongue is much easier to cut through, making much smaller pieces, and easier to chew for a newbie. As time goes by, you will eventually find that you will also enjoy the taste and texture of the stringy parts and the tip, and can include them as well. I have never ever had a problem with tongues from other animals.
Not sure what your overall health-situation is, but I should mention that when I first went RPD, I had very loosened teeth which moved so alarmingly when I tried to chew the raw tongue squares I had cut off with a meat-knife, that I was forced to leave out the raw tongue pieces for a few days until they softened enough for me to lightly chew once and then bolt them quickly down. Bolting raw meat down is what wildlife carnivores do, chewing is more something herbivores have to do to predigest/preprocess plant foods like grass .
Here's a link, among others in that section, which might be useful:-
http://www.rawpaleodietforum.com/important-info-for-newbies/sticky-advice-for-newbies-wishing-to-slowly-ease-into-a-raw-animal-food-diet/Re fertility:- If it turns out that you are not allergic to raw dairy, then I should mention that a number of RVAFers who experienced infertility in the past have reported success after consuming it for a few months. Others recommend cod liver oil, but, imo, Rosita raw cod liver oil is the only authentic, only genuinely raw/unfermented one worth buying. I also very strongly recommend consuming raw oysters to boost fertility. I can personally testify that it is not just a myth that raw oysters are potent aphrodisiacs etc.
