TTC, rainbow baby, overkill?

I recently had a miscarriage & have been very discouraged . I don't intend on trying to jump back in right away until I atleast get some answers what caused the miscarriage . I've been doing some research and think about starting to take Geritol , prenatals & cassava root & preseed. Before my miscarriage it took me 5 months on & off to conceive , idk if I have that much patience this time around . But then again the risk of miscarriage & complications is higher with twins so I'm wondering if that's a good idea . I just want to have a baby , has anyone tried Cassava root & had twins? What about Geritol? Also I hear the chances of having twins after a miscarriage are higher , has anyone experienced that? Any insight will be helpful