I was diagnosed with type 1 54 years ago. Yes, you will recover from this. It is not at all surprising that you have been feeling terrible, or that you have lost any muscle you originally had. The loss of muscle is a typical symptom of untreated type 1 diabetes. Thank goodness you got to see someone at a hospital clinic in the end. You could have ended up dead, to put it bluntly. Your body will take a while to recover from what has been going on. It won't happen magically overnight, but you should gradually feel slightly better day by day. You are likely to be ravenously hungry, as your body will be looking to replace the lost muscle as soon as it has insulin again and is able to do so. You are likely to gain weight rapidly as a result. The dreadful tiredness will also lift gradually. I would recommend taking it easy to start with. We are all different, so nobody can give you a definite date on which you will feel totally okay, but you will get there. You are only in your thirties and have your age on your side. Give yourself time to get over this and try not to worry.
Most of the time, type 1 diabetes is just a bit of a nuisance to be honest. Most people get used to coping with it fairly rapidly. I hope you have been told about needing to have fast-acting carbohydrate available just in case your blood sugar drops below normal. If there is anything you want to ask about, please tell us.
Best wishes for the future - and yes, you have got one !