Hi T.,
First, let me say ... no harsh judgment here. Frankly, I firmly believe you should NOT let a baby cry it out before their first birthday. In my opinion, before that time they NEED to know we are there for them. They NEED to know we will help them.
Ok... now onto your issue. As another mom said... expecting your little guy to change something like how he goes to sleep after 19 months is sort of a big change. I would suggest a gradual change.
I used to rock my daughter to sleep. We started the transition when she was about 13 or 14 months old ... so a little younger then her son. At first, I would rock her not until she was asleep....but very very sleepy. I would soothingly tell her "It's night night time, Mama is going to put you in your bed now". She would be so sleepy that she would hardly move when I laid her down.
The next step did involve a bit of crying ... but not long. I did this after about 3 or 4 days of the previous. We would go through our bedtime routine and then I would rock, pray, sing a song... and then say "It's night night time... Mama is going to put you in your bed now" This time she was more awake. The first night she cried for 15 minutes. Just as I was about to go in, she stopped. The next night, it was 5 minutes. The third night it was 2 minutes or less.
If she cried in the night... I would definitely go to her.
You want to make sure he knows you will still be there for him, but that he DOES need to go to sleep. I know one mom mentioned making sure baby was tired and not just following a routine. That's true... but I also know my daughter could be falling down bleary eyed tired... and would fight it all the way if I let her. She's just one of those kids. So, routine does help. Kids do much better when they know what to expect. So much in their lives is uncertain or difficult... trying to tell us what they want, trying to do new things.... that having a routine allows them consistency and confidence that they KNOW what is coming next and what is expected.
You can continue where you are. I would wait 15 minutes before you start checking on him. After a couple of days stretch it out to 20 minutes and so on. When you do go in, make sure you tell him you love him, that you are there and close by. Be calm. Be reassuring. Kiss his head, or whatever, I would try not to pick him up ... but you can bend down and hug him to give him the reassuring contact.
It could take some time... particularly since he is a bit older. I do believe at 19 months kids are aware we are still there even if they can't see us and therefore can grasp the fact that mama will come if I need her. So, trying to teach him to go to sleep on his own is ok at this point. Oh.. by the way... my daughter does really well. She may not go to sleep right away, but she will talk to her friends and tell them about her day and then drift off to sleep.
As far as rocking at nap time.... my daughter is almost 25 months and I am just now starting to do the 'put yourself to sleep at nap time thing'. The bedtime issue has long been solved, but she just had a very very difficult time settling herself down at nap time. I tried the same routine as I did with bedtime earlier... when she was much younger and it just wouldn't work. She would just play in her bed for 2 hours and not take a nap and then the afternoon was horrendous because she was so tired.
So...I guess what I'm saying is ... there is no need to disrupt his entire day at this point. Tackle one thing at a time.
Nap time is taking a bit longer, but I'm ok with that. They are only little for so long... so a few extra minutes holding my sweet girl and her letting me rock her is OK with me. I just don't think you can love them too much.
You will get through this.
The other thing you may need to consider that I just thought of ... is he may be going through a growth spurt. My daughter did just before her 1st and 2cd birthday. Whenever she goes through a big growth spurt her sleep is ALWAYS disrupted in some way. Now that she is older it isn't AS noticeable ... but it's still there. When she was younger, oh boy! We're talking up at 3am for 2 -3 hours and what not. So, that could be a factor in him not going to sleep right away.
Also, you said your husband was deployed. Have you spoken to him lately? or had any contact? Are you a bit more stressed then you normally are? Kids are very very perceptive. We try to hide things from them, but honestly, every time we fail miserably. Even if they don't know the REASON ... they know something is wrong. They know when we are stressed or frustrated. So, maybe take a self-inventory ... are you more stressed or frustrated? If so, he is probably picking it up. It just may mean you need to take some time for yourself, or just have a day where you and your little guy just have a quiet day at the park and not think about anything else.
Good luck. And ... thank you for your sacrifices for our country. It IS appreciated.