If you're lonely now your daughters left, it would be reasonable for your boyfriend to acknowledge that and be kind. I don't think he should "fill the gap" for you. Your confidence should be independent of him.
If he's just completely ignoring you/ghosted you of course you should dump him.
But if he just doesn't want to step in to validate your feelings all the time I can see his point?
When I was younger I had (ex) friends or dates who accused me of "coldness/avoidance" as I just didn't want to listen to their anxiety episodes or vents constantly.
I care for people but if someone just wants to trauma dump or emote at me to calm themselves down its not really a functional relationship. Nothing to do with trauma!
Adults should be comfortable being home alone, it may be a change but you will get used to it after a year or so.
Practically you could both plan some dates out or arrange a holiday so you have something to look forward to.
I don't think he should be available on the phone every night because you don't like being alone with no-one to talk to.
I'd expect boyfriend to help me with "big" life things like a move, be reliable, meet up for a cup of tea and a general chat (not just sex) and have a "reasonable" amount of messages and communication and pre-arranged meetups and dates.
I wouldn't really expect someone to be constantly messaging me or listening to me vent for hours just because I felt lonely alone at home. There are men like this but they might not be that emotionally healthy themselves!
For connection, a tip I'd have is to do less not more. You don't always need to go out and have complicated expensive hobbies or meet "fun" new people. Especially if you're not that extroverted. Take things slow.
Simple things like home exercise or decluttering (you may want to rearrange/clear out the home now that daughter has left) or trying new recipes.
For going out, you could just go out solo for a walk around the city in the day... stop in a few charity shops or free museums, get yourself lunch or a coffee and read a book.