My newborn will only sleep while being held, any advice to get her to sleep in the cot?

I made the mistake of not swaddling my baby from day 4 onwards and from then on she found it difficult to sleep in her cot. So she's been either sleeping on me or in her cot but after a long struggle. Recently (she's 11 weeks now), I started swaddling her again and it has worked! Basically I will rock her in my arms till she's asleep and I'll place her in her cot with a swaddle waiting. Once she's in it, I'll swaddle her and turn down all the lights. Sometimes I sit by her cot and pat her a little, to lull her into deeper sleep.