Hi,
I also have one copy of A1298C. I read a lot of scary things on the internet about it, but then met with a genetic counselor. She said that with only having one copy it has no effect on you or a pregnancy. The only effect it could have on your baby is if your partner is also a carrier, if the baby ends up with two copies then he/she could have problems, but just one is no big deal. So I was told.
I hope this helps you http://www.kimballgenetics.com/tests-mthfr.html
BTW..there are other subjects/questions in this same forum about MTHFR, maybe you can check them out.
I wish you the best and YES you def need to request further testing and treatments.