In urgent need of an apartment

Hi everyone again!
I arrived in HCMC 5 days ago, but as I've been working around the clock I haven't really had time to look for an apt. Now that I've started it seems really hard, as some agents I contacted haven't replied, some offer very expensive flats and some have very few offers.
What I am looking for is a small apartment (doesn't have to be serviced, I can clean it myself), it should be quiet, light (enough windows), have a fast WiFi, but I don't need a TV or cable. Ideally it should be not very far from the border of districts 1,3,5 and 7 (anything up to 10-15 minutes by motorbike would be ok). My budget for that would be around $400.
I am not excluding the possiblity of sharing as long as there aren't too many people in the house and I have a private bathroom.
I kind of need to move in as soon as possible (ideally tomorrow) as I need to move out of the hotel and anyway, I won't have time to go and see any places again until next week.
If you have any ideas please let me know. I'd be very grateful. Thanks!