Hi, PetraVanilla

Feeling much chi from your message. This usually happens when someone pours out their heart in what they write. Also speaks that you have potential yet to be fully tapped - no wonder you are not only just able to "feel" these unseen ones (he he, for the lack of a better word I label them as "d'anothers" after a popular movie here) but also practice Reiki.
You have down pat the basics of feng shui thus can't input much else in that. What you do need to add though to improve things is to address the limitations you are blessed with. This is usually best discovered using chart readings and/or meditations.
Ha ha. Nice to note that you like animals and so too your boyfriend

That is good as people who are able to be kind to animals tend to be generally so too with people. Makes great stress relievers too. Yup, adding a plant to where your goldfish(es) are will help in protecting them. Its just like chess. The pawns get sacrificed first not unless you gamble with your officers.
Fish especially those in aquariums are best kept outside or if they have to be inside they should be on the left side of the door - inside looking outside. Feng shui states that if its on the right side of the door - again, inside looking outside - it will influence the father in the family to have extra-marital affairs (or another girlfriend in your case). It may also influence the kids to defy their parents' advices and grow up to be irresponsible citizens.
Thus, the problem then arises in your situation as your boyfriend works with aquariums and it'll surely be a heated debate if you ask those be situated elsewhere. What you can do then is remedy it by using plants, making sure that the path leading to your main door has filters and cleanse your place as often as you could - minimum of once a week at least.
As for the frog, best to keep it as near the main door as much as possible and control it with a plant. Just like the money frog it, your frog, will draw in all the chi that is in the area. That is good if your neighbors are all well-to-do despite the economic crisis we are all in presently. But, that is usually not applicable to most of us and again if you dispose of that frog your boyfriend might take offense. Thus, to keep your relationship in order do what remedies that you could using basic feng shui - I'll give the ultimate remedy later.
For lizards, they are said to be similar to dragons. You know that dragons cannot be displayed in a Dog's home thus if your sign is that of a Dog best to place them outside.
Let's focus first on your ex- as this lesson will apply to your relationship now too. Not sure how deep you are into the paranormal but here we have what we call "sabit" or riders in English. These are either spirits, elementals or demons (yes, demons) who are attached to the subject and feed off on his life force or chi. Think of them as energy and emotional leeches. Some may have one but most have either 2 or 3 and sometimes even more. I don't yet have the gift of seeing these like those who are gifted with such sight but they are said to come too in various forms. Some are scary and some are said to look like even those Pokemon creatures.
There is a strong probability that your ex- has such on him. This is even more so if he has a lot of vices and is extremes in his changes of moods. Have you tried using Reiki on him? How was it? Did something try to block you from successfully treating him or not?
Now, taking these lessons from your ex- and applying it to your present situation is very important. As you can use the experience and knowledge you have now to improve your present relationship.
Your homework then is to first look back to the past events in your life. Write down those good and bad moments and see if there is a cycle in things. Then, highlight those that often appears may it be good and bad then check the sector using the Eight Mansions Formula. Enhance or remedy depending on the situation. Use Reiki not only on yourself to cleanse your chi but also those with you.
Lastly, strengthen further your connection to Him. Its okay that you do not often go to Mass. Ha ha. I do that too as I don't like our priests here who tend to give political speeches instead of lessons to improve one's spirit and faith.
As for the ultimate remedy, there should be an altar facing directly the main door. It doesn't have to be a special one. It could be a simple desk with your Bible on it where you would pray every morning and evening. Take note that as its an altar it has to be regarded sacred thus you shouldn't allow anyone to place their cellular phone or such on it while its being charged.
Almost forgot, for the plant in your bedroom make sure it has to be the one with fat broad leaves not the spiky or thin ones as that would make both of you "hyper."
Do update me on your developments and if you have questions still

Ha ha. Need to post a bit more to activate the program given here. Getting tired of doing things by the long hand method already :P