Afflicted Lycanthrope is not only advantageous but often problematic. It will not simply make you stronger, especially until you gain enough ranks in Control Shape skill. So If I were a DM, I will immediately apply all the aspects of the template. But I will not give you any additional XPs at that time.
Assume your PC has 66,000 XP (just enough for becoming a ECL 12 character) when afflicted by werewolf lycanthropy.
Now your PC is a
*Level 14 Character (because your HDs increases by 2)
*ECL 16 Character (because afflicted lycanthrope has LA of +2)
This is what happens according to the core rule.
Then, If I were a DM, I will keep your PC's current XP total as 66,000. And just treat your PC as a ECL 16 character when calculating XPs you gain from each encounter from now. So your PC will start to gain much less XPs for each encounter, comparing to other PCs.
And your PC will get another level only when the total XP reaches 136,000. Enough to become an ECL 17 character.
As you are afflicted by Lycanthropy, you can be cured. I will not adjust your PC's XP total in this case, too. So, at that moment, you may gain new levels. By RAW a PC cannot gain more than 1 level at a moment. So if your PC's XP total is too high, it causes problem by RAW. But if I were a DM, I will rule 0 that part and allow you to advance 2 or more levels immediately.
Or maybe it is OK by RAW. Your ECL does not change (or lowered, dpend on XP total at that time). If you have 120,000 XP at that time, you will just become, say, a Werewolf Swordsage 12 (ECL 16) to a human Swordsage 16 (ECL16).