Salsa - Have you thought about seeing an Osteo? They work wonders on bubs that have colic and their sleeping changes dramatically.
I can highly recommend that you see either a Pead. Osteopath or someone that specialises in Peadiatric Craniosacral therapy

At this age i would go for a walk at the difficult time to get MJ to sleep, but mostly she fell asleep after or during a feed. yes it does mean that they dont self settle, however i think that it is something that they can learn later on when there is a better undertanding of what is expected of them.

As some of the others have said - go with the flow, if you notice tired signs stop stimulation and maybe have a cuddle, I didnt put MJ down awake when she was a baby much (at times i did) and she now goes down awake and most nights there is no problem anymore.

Around this age there is a growth spurt too (maybe the tail end of one) and so then things will change again.
Also your DS will be starting to become more interested in the world around him now, make sure that there are times of stimulation and play as this will help him sleep after.

GL - it gets easier (as i am sure you remember), but takes time and IMO i would rather take things slower and have a happy baby than push firm sleep times (not saying that you are doing this)

HTH