Oh Frills 
I don't think you ever really feel 'better' or get used to losing your child, it is part of your reality now and I think you come to accept that at a point in time but it happens when it happens, its like asking how long a piece of string is.
I know you can't see a future for yourself now, but I promise you one day you will be able to look towards tomorrow, then eventually next week and next month, like anything it just takes time, you just have to be patient and process your feelings as they happen and not try to dismiss them because you want to feel better. You won't even notice yourself accepting that this is your life now, it happens so gradually, but in a few years time and you are looking back you will see it, its just hard to notice when you are actually living it.
I lost my son nearly 15 years ago now and I lost my daughter 6 years ago, and I still think of them every day and talk about them all the time and miss them every moment, and some days, even now, it hits me like a ton of bricks, but, for the most part I can look back and be grateful they touched my life, even for the short time they were with me. You will one day too.
For now, you need to make a plan when you are having one of your 'better' days. Email your friends who are pregnant or have had a baby recently and tell them how you are feeling and ask them to be patient with you, make some meals and freeze them so on one of your days where you can't function you can stick a healthy meal in the microwave, maybe talk to your work (if you work) and have a code word that you can say to them so you don't have to explain why you are taking the day off (I did this after I lost my daughter). In other words on the days you can function get prepared for the days you can't.
The biggest thing is to keep talking, don't hide your feelings away for fear of upsetting people, your son was here, he was real, and he will always be your son. Maybe talking to a counsellor is right for you, maybe it will be a family member or friend, but do talk.
Be gentle on yourself, I promise the dark cloud that you are living in just now will lift and become part of your sky when you are ready.
(((HUGS))) 