Well, calling it "so early" is probably unfair - after all, your bike is about 9 years old, with 70k miles. If you had a car of similar vintage, you'd not be surprised to have some suspension issues.
Having said that, it may be unusual. I do not recall any reports of this issue discussed on the forum.
You may have to spring for a new part. Here are the addresses of part fiches that you can utilize.
For that type of part, a dealer is probably best - but you can always try the recycling places. I do not know if the US-based ones ship to Thailand, but if you'd like I can post some contacts.
Final thought, though: front end being "loose at low speed" is not consistent with a steering damper problem
. A flaky ball joint does not make the damper stop working in such situation. More importantly, the damper is ineffective in slow turns - its function is to prevent rapid oscillations at speed, that could lead to a "tank slapper".
If the sensation you perceive is new, you should investigate it. It could be a problem in the head bearing. More likely, though, it could be related to your tires. Is the inflation pressure correct? Is the thread in good shape? Is your tire profile (cross-section) still round? I had Metzelers Z6 on my 'RS that wore in a triangular fashion, resulting in a ridge along the perimeter; the tire tended then to "fall into the turn" almost by itself at slow speeds, although it was quite stable at high speed.
Regards from a very snowy New Jersey - 2ft since yesterday and counting. While writing this, I got a call from our County Sheriff's office, declaring a local state of emergency.