Should i cut my losses?

Of our guest list I have 7 people who will definitely get invited (immediate family), my fiance has 51 family/friends he wants to invite so it is already quite unbalanced.


I dont have any close friends, mainly due to moving around a lot & always finding myself at different life stages to those I had become friendly with & drifting apart.
There are 3 girls I used to work with & we have maintained contact via a group chat that we catch up on every week. In the 6 months since we have not worked together we have tried to make plans a few times but it keeps falling through. Each time I have kept myself available but one or more of the others has had something come up. Life gets busy, I get it, I'm not mad about it, it's just background.
When I announced the engagement they all assumed they would be invited to the wedding. I half-jokingly said that I'd need their addresses first for invites. I was intending to invite them as they are the closest I have to actual friends.
We are now 4 months down the line, the wedding is in October so planning is in full swing. They have all said multiple times how much they are looking forward to it. Yesterday one of them said 'let us know if tou need any help with wedding stuff', I responded that all I needed was addresses for invites & still not one of them has sent their address to me.
I'm feeling like I should just walk away, I'm fed up of trying to make & maintain friendships & tbh feeling like a failure in life that I don't have any friends. Would you just write off this group of girls if it was making you feel rejected & miserable at each interaction?