Hi Wei
So sorry your having such a rough time of it. A wedge is a pre-made rolled up blanket in effect, so rolled up blankets will do just fine. Its excellent news that the naps seem to be getting better, and she is now proving she can fall asleep on her own, even if at this stage its taking 30mins the time it takes her will get shorter and shorter, I promise.
With regard to bed time and indeed all the night time wakings, is she getting enough sleep during the day to get a good restful sleep at night? she may well be extremely overtired by bed time which would explain why she cant settle and gets very upset. My DD is exactly the same, if the days been too long or she hasn't had good naps she is far too overtired to get to sleep at bedtime, she is now 16weeks 4days and is still the same.
When I started EASY I started on the 3hr EASY based on the one set out in Tracy's book page 25 'typical EASY day for 4week old'. I didn't worry too much about the timing's tho and I worked more on getting the right amount of sleep from her first, so for example if she woke at 7am and fed for 20-30 mins then A time for 30-40mins I new I wanted to get a min of 1.5hrs sleep from her before her next feed even if it took 1hr to get her to sleep I would still let her sleep until she'd had 1.5hrs, obviously if she woke sooner hungry I would feed her and start the cycle over but again I would try to get 1.5hrs sleep the next time, aiming to get 3 1.5hr sleeps and 45min catnap before bath, I would seldom manage to get the last 30min nap before last cluster feed but wasn't too worried about that.
As Tracy says 'good sleep begets good sleep' and in doing this I think it helped establish good nap times of 1.5hrs rather than 30mins here and 45mins there. If you get this part of the routine sorted then gradually as she gets better and better at falling asleep for her naps you will be able to bring the timings in line with the 3hr cycle. And hopefully if she's getting enough sleep during the day her night time sleep should improve.
The other thing is I found that a 7.30pm bedtime is just too late in the day for her, even at 16weeks a much better bedtime is max 7pm although depending on how well the day has gone even that can be too late and a 6.30/6.45 works best. I think some babys simply need more sleep than others, which is definitely the case with my DD as even now the textbook says she can be awake 2hrs at a time which she cant she can still only manage 1 session at 1.75hrs and the rest at 1.5hrs otherwise bedtime is a nightmare.
Lastly, sorry I'm on a roll here, I didnt implement a rigid bedtime routine of feed, bath, lullaby and bed for along time, I think mainly because the days were quite messy, sometimes it was just too late, othertimes I just couldnt be bothered as I was tired myself... BUT and it was a big BUT when I finally got my act together and started doing the same routine before bedtime every day suddenly she got so much better at going to sleep at night and slept so much sounder, so I really cant Emphasise enough how important a relaxed happy bedtime ritual is.
Sorry I've gone on so long, hope its helpful
Big Hugs
Nik