If i have trichomoniasis and i don't get it cured could it turn into a serious disease?

No, but.....: Trich is an STD and needs to be treated. It is transmittable to others and will cause a vaginal smell like you wouldn't believe! So to avoid embarrassment, treat it. But it won't necessarily cause a serious problem like, say, chlamydia or syphilis or other STD's.

Possibly: Possible complications from Trichomoniasis that is left untreated include the development of Pelvic Inflammatory Disease in women. Complications in both men & women can ^ risk of infertility.