My dream future

We met online at the start of lockdown and met socially distanced for an outdoors coffee and walk with the dogs. He gushed about how fantastic I was and how he would marry me this year if he could. I fell head over heals and we became each other’s bubble spending all our spare time together. Those first few months were incredible as he promised me the world and a future I wanted. 
In July I found out I was pregnant, but miscarried a few weeks later. He was struggling with his business and staff on furlough and didn’t give me any support. Since then, it has gone downhill, he’d spend all his spare time with his friends helping them with projects and would not see or speak to me for a week and saw nothing wrong with this as I pushed to see him and talk to him. We’ve seen each other once in the last 6 weeks, we’ve not had sex since I told him I was pregnant. He says he’s too busy as I’m calling and texting daily to only get ignored. Last week, when he finally replied after 3 days, he ended it in an argument. 
I’ve bombarded him with calls and texts as I don’t want this and want him back. He’s mostly ignoring me, apart from the odd offering of a text every 3 days or so. I don’t know how we went from talk of marriage to this? Was I just a lockdown distraction for him? Has he met someone else? Why does he ignore me? What the hell happened? 
I know I should find my confidence, self esteem and sense of self worth and move on... but when I was promised my dream future, that’s easier said than done.. I’m now broken!