Which Fluoride Toothpaste?

Throughout my care i have asked my team about dental care, no one looked at my teeth before treatment due to COVID, I had to stop using my normal toothpaste as it hurt so much, I asked the team what to use, they recommended children’s toothpaste which I’ve been using since and it’s fine, they said I could go back to my normal toothpaste when it didn’t hurt, so this is what I’ve done but it has caused ulcers  and my tongue has been stinging since.  I’m really confused as the children’s paste is low fluoride but everyone on here says high is better. I was prescribed gelclair once 4 weeks post treatment but told it was a one off. I was only told this week (14 weeks post) that I should still be using a salt mouth rinse, I stopped after 8 weeks (no communication with them 8-14weeks).  Can someone recommend a toothpaste, mouthwash I can buy as the hospital won’t prescribe it. I don’t have an NHS dentist and doubt any will accept me now

Thank you Pamela