Help!

Hi guys,

My plant suddenly had its leaves turn yellow, brown and then just started falling off. The plant doesn't give a smell off anymore either

So, here's the deal:
1. Grown outside in a pot on my balcony (sub-tropical climate, hot, but protected from rain)
2. No additives or special soil is given. These products are very hard to get here as well, so that's kind of a challenge.
3. Watered about 1-1,5L a day before (went great for weeks), but now I don't give it too much water anymore to make sure I don't overwater it.
4. I've been seeing little red spiders everywhere, but how do I remove them?

Most of all: I'm a beginner, first grow ever and I don't know much about it. Also, I can't get hold of PH meters, etc etc. This country simply doesn't have it. So here's the catch: how do I kill the spiders, keep the plant alive by adding maybe nutrients (???) but without the professional stuff. I can only get simple stuff here

 

Thanks for the reply! Here's the thing: It' never got any direct sunlight but was growing beautifully, suddenly it just stopped. So I'll try putting it in more direct sun light!

I don't think anyone poisoned it, its very well hidden. Hopefully I'll still get something out of it Because it's a very special plant actually, that's grown in the mountains over here in south-east asia, in a rather secluded country. So i'm very curious as to what it will be like.