Help with 9yo boy

I am a single mum with 2 children, I don’t have much of a support circle. My youngest, 9yo boy, I have always found harder to parent. I love him dearly and only want the best for him.
I have issues from toileting(day and night), sleep, listening and a big one is lying.
I have been his main parent most of his life, having some contact(phone) with his dad.
Discipline wise I have tried-
limiting his screen time and putting a passcode on the iPad so he is unable to sneak use.
He doesn’t have favourite toys to removed from him.
Making him do extra jobs around the house.
Talking to him and explaining why I’m getting angry with him, what I am wanting from him etc.

I am lost, and I’m starting to not enjoy parenting, I feel like I’m failing him. Please can anyone give me ideas on what I can try?