If you are having hypos all the time, you need to reduce your insulin doses.
Humulin comes in different types (quick acting, mixed, etc) so it's not possible to comment on those doses without knowing the type.
Your work out your carb ratio by counting the carbs in your food, injecting insulin according to your ratio and adjusting the ratio if the resulting BG is too high/low. DAFNE is just very sophisticated trial and error.
If you cannot go on a DAFNE course then
Bournemouth has a decent (if a bit basic) resource on carb counting.
In simpler terms, I started out on 8-10u of Humalog for a typical meal, had to stop taking it entirely at the peak of my honeymoon period (or have 1u with 4 wheat biscuits and 2 scones to avoid a hypo) and am now back to 3-4u.