@solosunflower sorry you're going through this, it definitely sounds like 'colic' (although that is a broad and unhelpful term as it doesn't suggest a route cause) - and know this isn't the norm but it is common.
Have you tried gripe water or infacol first off? Or try to get hold of baby gavischon (which is similar to infacol as far as I know). Heart burn is likely. Gripe water is an absolute miracle for releasing wind and it's all natural ingredients.
Another thing that does help is baby massage especially to release stubborn trapped wind which drive babies crazy. There is a colic protocol. I suggest you reach out to a local doula and they can come over for an or so and train you 1:1 (rather than going to a baby group to learn it). Most doulas know baby massage. And they might have some other tips and would be nice to connect to an experienced mother/baby carer.
One tip I got told early on if baby is kicking off is change the temperature and scene. So go outside with him or run a baby and put him in it.
Another thing that can help with colic is craniosapal Oesteopathy - have a Google of who is local and have a chat with them. Sometimes a readjustment is needed to make baby happy.
Re your mum - she has proven over and over that she is not to be relied on. This is incredible sad and it's hard to not let that occupy thoughts. As you parent at the different stages unfortunately memories surface and a sort of grief sets in because you start to release that you didn't get the mum you deserved. But know you're breaking the cycle, it's such important work, your ancestors and your future blood lines will thank you for it. It's so hard though. Solidarity with you. I would definitely seek some therapy via the NHS if you can really just for yourself.