Hello Laura and welcome to the forum, glad you've joined us 🙂
Please don't blame yourself, running your own insulin supply around the clock come what may is really hard work and we all go through times when things just go haywire even though we know what the aim is.
Do you have a good diabetes team you can ask for help in getting better control? If you do please ask them to help you or if you're seen at your gp surgery ask for a referral to a hospital clinic. There is an assumption that if we've lived with it for a long time we know exactly what to do but diabetes is a constant work in progress and we all need some fresh input and support at times.
Are you on MDI or do you use a pump?, are you struggling to inject regularly or are you guessing at a dose and hoping for the best? These are common things that happen and I speak from experience. Make little steps to improve things for yourself, start to test regularly if you're not doing so, record the results even if they're not the results you'd like to see, then have a look at where you can start to improve things. Looking at the whole picture and seeing a big, out of control mess is overwhelming and prevents us from trying to improve things. Break things down into bite size pieces and if you focus on one thing at a time you will start to see results. Start with testing and recording, ask about carb counting if you're not already using it -and don't beat yourself up. 🙂
Have you been on a course such as DAFNE for carb counting and dose adjustment. please ask your DSN if you haven't been offered one.
I've got eye and leg complications amongst others and went through a long period of struggling even though I knew what I should be doing. Joining this forum and reading what others were doing and using to get better control was the best thing I have done. Please ask us for help on any problems you're facing , there's a wealth of experience on here and between us all I think we've experienced most things. I wish you well. 🙂