I would agree with the post by kingofkings..
You need to rework the fish you have in the tank. Pick which one of the lot is your favorite - get rid of the rest and re-work the tank around your favorite fish. Make sure the fish you pick can live in the size tank you are providing for the length of its life (look at a species profile on the fish you pick). You can set up the tank decor and tank-mates around the fish you pick.
As for your filter - I know I started with low end filters before I started to do research and realize filtration is important and its one of those thing that is just worth the investment. You can look in the DIY section of the forum and find lots of different filtration types that you can DIY for cheaper than buying an expensive one. If there is an expensive type you like go to Craigslist and see if you can find one for sale. A simple HOB does not cut it especially on larger tanks - you can use as a second filter but that is about it. When you have mechanical filtration you have to make sure you keep up on keeping it clean when those filter pads sit there, esp. for a long time uncleaned or changed they get clogged up with nastyness and all of that stuff starts to decay and it gets back into your tank. I would recommend a nice canister filter (I find them easier to deal with then sumps) or a sump (they work great too). Whichever route you go make sure you check the filtration rate before you buy it. You want at least 3-5x the turnover rate (gph - gallons per hour) then what the total gallons of the tank is. I have a 150gal tank so my gph should be at least in the range of 450-750gph. I always shoot for more gph then 5x. It just depends.
As for things breaking - they do. HOB's get clogged up - esp if you have sand in the tank. The impeller/area gets warped easily and they start making noise and just don't perform as well. I only use them on small tanks (10-20gal) or as a secondary form of filtration.
It is all a learning experience, I have been there before too.