Im sorry to tell you but you are WAYYY overcrowded. The fish that you have in there (even taking out the swardtail) all of them put together require AT LEAST a 50 gallon tank. And you have some problems that I will talk about later but.
First off, the red velvet fish, while it may be small now gets up to 11 inches in length so that fish once full grown will eat all your other fish. The tetras NEED to be in groups of 6 or more as they are schooling fish. And the guppies, mollies, glofish will all get to be up to 4" in length once full grown.
So if you cant get a bigger tank then I would suggest getting rid of some of the ones that you already have, if you don't decrease your numbers for that tank then the fish will eventually get stressed over the dirty conditions and anmonia levels and will die. If you want you can try to clean the tank EVERY DAY and maybe that will work, but only do 1/4-1/2 water changes at a time. But I don't think you have the time to do that.
So if you cannot afford another tank then I would suggest getting rid of the tetras, redvelvet, and the gourami then you would be at a reasonable number. If you really love your fish then you would do the best for them. And having the glofish, guppies, cories, and the molly in there will be a fine mix of colors and swimming level fish so it will give you a variety of fish!
Good luck, email me if you have any other questions.
I don't think that that sounds overcrowded I would just not get any more fish unless one passes away :( . I don't think that the guppy and red velvet fish are breeding because they are in different families. And a red velvet fish is not a livebearer and a guppy is.
And if t=you are going to have the swordtail seperate I would either get a breeder net and put that in your tank with him in it or get a 1 gallon tank with a pump. For the filter I would get a top fin that is what I have good luck.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.