Sorry to hear that you have been dealing with bumps on the back of your tongue. This question is impossible to answer definitively without actually being able to examine you. However, there is something called circumvallate papilla which are on the back of your tongue, at the junction of the anterior 2/3 and the posterior 1/3. There are a number of different types of taste buds in your mouth, and on your tongue (ex fungiform, filiform, foliate, circumvallate). The circumvallate papilla are normal structures and stick up taller then the other taste buds (papilla) in the shape of an arc, or "V" at the junction of the oral tongue, and the base of the tongue.
This may be what you are seeing when you look at your tongue. Most of the time they aren't very easy to see because they are too far posterior, but if you stick out your tongue and look in a mirror you may be able to see them. There are a number of different possible things that can cause bumps on your tongue, however without being able to ask you more questions and take a look at the bumps, I would just be taking random guesses as to what they are. Bottom line is if they persist and bother you, I would get them checked out. If you primary care doctor
can;t tell you what they are, an ENT will likely be able to figure it out for you. Best of luck. Hope this helps.