Insulin is prescribed to T2's in the main when nothing else works...
But as Sue's says, having a look at your diet might provide you with the ability to avoid the insulin if you can.. You may be able to tweak some of the foods that you eat, either type or portion size that impacts on your blood glucose less..
If you'll not testing, ask your clinic for meter and test strips, so you can see how your diet is impacting on you blood glucose so that you can at least attempt to alter your diet...
Insulin can create all sorts of hoch pots problems from hypo's, to effecting your driving licence, health and life insurances etc..
As to an 'envitable weight' gain, a load of tosh to a certain extent.. As I am 1 stone lighter than my prediabetic days.. I went from 9 1/2 stone down to 6 1/2 stone :shock: before going onto insulin.. As the insulin sorted out my blood glucose levels I started to gain weight (weight that I needed to be healthy) but in the 21 years I've been using insulin I've still never managed to get past the 8 1/2 stone mark