AIBU to feel lonely and tearful on maternity leave?

Based on my personal experience, I want to say that this will pass. I think the first year is the hardest, it’s a massive adjustment and after the initial period of everyone swooning over a newborn, it does tend to get quite lonely. But I also don’t want to just brush over what you’ve shared about PND, please do reach out to your HV my luv. It sounds like some adult company is really valuable to you and so it’s understandable you don’t want your family to leave. I wouldn’t say I made any long standing friendships from baby groups, but it was nice to be around adults and get moments of adult interaction. Big hugs to you darling. All these years later and I still remember just how lonely those days felt ♥️

You might have PND or you might just be feeling lonely and isolated because you are.
When DC were small I made friends with a nanny who gave me really good advice that I followed. She said: leave the house every day. Make sure you have a conversation with an adult at least once a day. And make sure you have a date with your DH once a week.

The once a day outing meant making an effort to go to baby music, playgroups, coffee mornings, baby yoga. Most of these things are really there to help new mothers connect. Church playgroups were lovely. Full of older volunteers who would take your baby for a moment while you chatted to another mum.

A group of new mums in our area used to meet up once a week for coffee in each others houses, and once a week for lunch in a local cafe. You might have to make an effort and suggest this to a few people, or just invite a few mums for meet ups in the park. See who says yes, as they will be, like you, wanting to make friends. Don't worry if you don't have much in common. At this stage of life, just having an adult to swap baby chat with helps.

And for the dates with DH, I recommend not going out for dinner, as you won't have much to say to him if you are shattered and home alone with the baby, so always go to a film, comedy night, music gig, theatre show - any new shared experience that you can chat about afterwards.

This. You need other people in your life more than once a week. Human beings were not designed to be home alone all day with a small baby.

You don’t mention a single friend Op?

Have you considered joining any groups? Baby sensory groups? The app “peanut” to meet other mums? I think it’s understandable to feel the way you are feeling in your current set up, sounds like you are sad because you are lonely and in need of some adult company OP xx

You do sound "down in the dumps"
Maybe a trip to the GP or a chat with the Health Visitor may rule out anything medical.

Mum and baby groups are great on mat leave. Even when baby is small ypu can meet mums in the same boat and have a brew and a biscuit.
Take your little one swimming. Its never too early. It also tires them out, most babies love time in the pool.
A good brisk walk in a park with a cafe may lift your mood, especially on a lovely autumn day.
Have a little "at home" pamper. A lovely bath, do your hair, paint your nails can make a world of difference to lifting your spirits.

Wishing you and your little one all the best xx