Stocking is a complicated art...but briefly, here's how we can tell you're overstocked.
A useful guideline (not a rule!) for stocking, if you have standard tropical fish, is 1cm of fish per two litres of water (or one inch of fish per gallon, if you prefer Imperial!). You always use the enentual adult size of the fish for your calculation, as fish need room to grow.
So, you have;
4 mollies at approx 8 cms each = 32 cms
6 platies at 3 cms each = 18cms
2 widow tetras at 6 cms each = 12 cms
2 'see through fish', which I'm guessing are glass catfish, 10 cms each = 20 cms
1 fighter at 5 cms = 5 cms
1 sucking loach at 30 cms (yes, really, that's how big they grow) = 30 cms
= 117 cms, when your tank should be holding around 25 or 30 cms.
Added to that some of your fish are shoalers and need to be kept in larger numbers; the glass cats in particular fare very badly if not in a large shoal of around 8 to 10 indiiduals, and the widows will very likely nip your fighter as they need to be in groups of six + to keep aggression to tank mates down. Plus the sucking loach won't even be able to turn around in a tank of that size once it gets anywhere near full grown.
