Hi Josh and welcome to Tropical Fish Keeping forum.
Well, I've read through this thread, and I'd like to offer some general advice on the problems I see.
We are all limited by our aquarium size as to what fish we can keep. Fish are living creatures that have certain requirements, and each species can be similar or different in this. But if these requirements are not met, the fish will be under stress and stress causes health problems; it wears down the immune system quickly, causing the fish to be susceptible to all sorts of issues it would otherwise not have. So it is very important to know what the fish you "want" need, and be able to provide that, or look at other fish.
A small tank like yours is going to limit the type of fish you can have, and then the number. As you have already learned in this thread, angels, gourami, glass catfish are not possible. That leaves you with small fish, which are usually going to be shoaling fish; this means they must be in a group or they will not be healthy--or happy, and the two are related with fish.
Ember tetra need a group of 6 or more. That is a perfect fish for a planted 45 litre aquarium. But, what are your water parameters (hardness, pH)? Ember tetra are wild caught fish and they need soft and slightly acidic water. A swordtail is the opposite, it needs harder basic (alkaline) water. You should not mix the two, as one is going to be fine and the other not, which means more stress and sick fish. It is better to have a successful aquarium than one where you have fish regularly diseased and dying, that is very frustrating.
Neons also need a group of 6, and six neons in a 45 litre tank is getting full. A group of 6 neons and 6 embers would work, with maybe 3 Corydoras catfish for the bottom. That's it. But this means your water has to be appropriate.
If you want more fish, they will have to be small fish; but there are several possibilities. The Embers, one of the dwarf rasbora fish like Boraras brigittae, the dwarf cory species like Corydoras pygmaeus, a group of pygmy sparkling gourami, scarlet badis, ...there are quite a few, these are all shoaling fish, checkout the profiles on these and see what you think. But again, these are all requiring slightly acidic water to slightly basic.
Hope this helps a bit.