Hey, I sat Higher Chemistry last year but was in a very similar situation teacher-wise- essentially I self taught myself the course using various textbooks/other resources and ended up with an A1.
The website JabChem is brilliant for AH, as it contains the 'Traffic Lights' which are just summary notes containing absolutely everything you need to know. Additionally for AH, JabChem contains summary notes and exercises for each key area which you may find also useful.
The brightred and how to pass books for AH are also great, and have great summaries so are ideal for going through yourself. (I have a pdf for the how to pass book if that would be useful)
I think the best notes for AH however are on scholar, and they have 200+ page documents going through each unit in depth- if you do not have access to these please let me know as I can send you them for all 4 units!
Kirkcaldy High has an excellent site for AH chemistry, containing complete notes as well as tutorial questions by key area with marking schemes as well as tonnes of practice questions.
KIRKCALDYLikewise, as others have said there are plenty of Youtube videos (eg Miss Adams) going through everything.
I hope this helps! Let me know please if you need any of these documents