You're probably loosing weight because you are so hyperglycaemic, your body isn't getting energy from the food you eat because the sugar is in your blood and can't get into your cells to fuel them, so your body thinks you must be starving and starts burning up your fat stores to give you energy.
You're probably tired because you are hyperglycaemic. Obviously, no being able to get fuel into your cells makes you pretty exhausted.
Dizzy spells are probably also attributable to hyperglycaeimia, which can cause vision issues.
What medication are currently taking to control your diabetes if they've said there are no more pills they can give you? Depending on what medication you are on you might need to be cautious about diet adjustments to bear in mind hypo risk.
Do you know what they are suggesting you start injecting? Insulin would be the obvious one, but there are a variety of other injectable medications for type 2 diabetes, which may be trialed before insulin.
If they are suggesting commencing insulin you might want to consider asking for a cpeptide test to see what your insulin production is looking like. A key element of type 2 diabetes is hyperinsulimia, the production of more insulin than normal as your body tries to deal with insulin resistance. If you are producing lots of insulin then adding more with injectable insulin may not actually be that helpful and you might be better off looking at diet adjustments, exercise and weight loss. Some type 2 diabetics find that the strain on their insulin producing beta cells of the over production of insulin effectively wears out the beta cells and they stop working, they would not be producing enough insulin, in which case a move to injectable insulin would be required.