One Fish, Two Fish

Ok...many of you know that Brandon and I have had a 40 gallon fish tank for at least 2 years now and we have always had the best fish! At one point we started with 4 molly fish in the tank and they ended up having like 24 babies. It was awesome. Then, the young fish slowly died off due to their agressive parents who don't play very nice. We then started adding mickey mouse fish to the tank. They are great fish too, but holy cow, that made the fish crazy sick and we were always having to treat the tank. But somehow we got through it and like the mollies, they also ended up multiplying to like 16 fish. They went through 2 moves with us and we never had a problem with them. So, you get the point. We take well enough care of our fish were they feel comfortable having lots of babies. Well, the other day, one of the big guys died. I am always sad to do the whole "burial at sea" thing, but do you really have much of a choice? Anywho, well fluke, right? Well, over the next two days, we have had about 5 more fish die! After the first 2 died, I decided to treat the tank for an ick outbreak, but apparently it didn't work! Now Brandon and I have about 4 fish remaining and that is a serious estimate because they spend time in this castle that we have and only really come out at night. Well, here is my predicament. Do we refill our tank with fish? Is it worth it? Here is my list of pros and cons:

Pros- pretty to look at, the cats love watching them, decoration that I severely lack at the moment, and we just like fish...

Cons- The tank is a beast,it is a HUGE pain in the ass to move, algae outbreaks(!), cleaning the tank, dying fish, expensive filters

Here are what the fish look like:

This is the Mickey Mouse fish...see why they call it a Mickey Mouse fish?


This is what a pregnant molly fish looks like. Talk about beastly!


We had pretty much all these colors of molly fish...The white one was our first big guy to go this time.


I know this is a random and ridiculous post, but for reals...
If these fish made it through 2 ridiculous moves, what the hell is going on?!! I would have expected them to die off when we first transferred them to the tank, but now? They've been in there almost 2 months. Anyway, should I get more?