Never quit, you have a real problem looming with that many fish (and that type of some of them) in a 10g aquarium. My earlier comment about never too many plants was in jest (as was Aunt kymmie's similar), but there is no jesting here. This is a disaster waiting to happen, but we can suggest how to resolve it. What I will say will be direct and blunt, and please accept this as beneficial help for you and your fish.
First, redtail sharks require a large tank; they grow much too large for a 10g, and like all fish they grow throughout their lives and if they are in too small a space they will be stunted, which briefly means the internal organs develop but the external doesn't and innumerable health problems can occur. Crowding also affects a fish's behaviours. The fish is not in good health because it is under stress constantly. This applies to any potentially large fish in a small tank. It is not kind, it is quite cruel to the fish to put it through this ordeal.
This applies to the angel fish, sharks, clown loach and blue gourami. These fish are not suited to a 10g tank, please see if you can return them to the fish store; many stores will understand such a predicament (many of us went through this at the beginning, I know I did) and offer a credit on supplies for your fish; even if they just take them, it will be for the good of the fish. Another point, these fish need company, their own species; clown loaches are highly social fish that interact, but at a mature size of 8-12 inches they need a huge tank for 5 or more of them.
And not only the fish you take back, but the others in the tank, who are also under stress from having these other fish in there; they simply do not have the "room" to avoid each other, highly stressful.
Tetras are shoaling fish, like the loaches I mentioned, and must be in a group to be "happy" and thus free of more stress which brings on poor health. Same for corys; at least 3, preferably 5, in a group to be happy and healthy. You don't have room for 5-6 of the bleeding hearts, corys, black tetras (black skirts presumably), zebra danio and platies in a 10g. You need to decide which fish you want, and return the rest. Out of all these, a group of 5-6 of one or two of the tetras/danios/platies plus 3-5 corys would be max in a 10g.
Lucky you have plants, as they are doing an incredible job of preventing things from being even worse for the fish. And a weekly partial water change of only 10% is not anywhere near sufficient; 50% of this tank needs to be changed weekly, and with all these fish it should 3 times a week. Even that will not prevent poor health and deaths down the road, so please consider removing some of these fish.
I won't get into the plant problem as the fish are far too urgent an issue.