If you're in Belgium check out Decathlon for cheap sleeping bags and tents. My girlfriend and I bought the T3 Ultralight last year and it's served us well over several trips bike and car camping. Last summer they had a deal on the T2 (2 man, 2kg) + sleeping bag (800g) + self inflating sleeping mat.
No stealth camping on the main land for me I'm afraid, only in the UK, which is even denser populated in most parts. I've got on ok.
I'd say get a job and save up a few hundred more euros so you can at least no have to worry about eating. A couple of weeks agency work will get you plenty.