Well, I will try not to make any real jokes...
I been buildin tanks for 20 years, and the best advice I can give, unless you can be taught hands on, is have someone else build it. There are simply to many variables to really teach someone online, and most of the online info is pretty far off from what really needs to be done. Everything from what surface to build on, what clamps to use, how to use a caulking gun, (there is a skill involved) to what silicone to use and why, how thick the glass needs to be, how to clean up the mess; how to keep the seams even (thickness,) that barely even scratches the surface of the topic.
Guitar strings will get it off the stand, (get a few packages.) Guitar strings will get the tank apart (another few packages.) Razor blades, (a carton of them,) Methyl Ethyl Ketone, steel wool, elbow grease, and about 24 hours of labor, to clean up the mess. And yes, if I were you, I would start over. At the same time, though, I suggest you have a professional build it. DIY can be done, don't get me wrong, but in the long run, having it built will be cheaper.