Morning: "Humulin M3" is a mix of 30% quick acting and 70% long acting (12-18)
Night: "Humulin I" is 100% long acting (12-18h)
Carbs: "Humalog" is quick acting
The problem I see here is that the mix insulin "Humulin M3" is always giving you quick acting insulin that last for up to 4 hours. How to know which effect is coming from the humalog and which is coming from the 30% quick acting in the mix?
It would be better to just inject the basal insulin "Humulin I" every 12 hours and to use humalog to cover the carbs you eat and for corrections. This way you can better identify how one unit of humalog is working for you. This would look like this:
Morning: Humulin I 100% long acting (12-18h)
Night: Humulin I 100% long acting (12-18h)
Carbs: Humalog quick acting
Furthermore I would question the "Humulin I" itself. I have used this type of insulin for years. The problem is that it does not act evenly as a basal insulin is supposed to do. Instead it has a peak with higher insulin activity around 4 hours after the injection. For me this made me prone to lows around noon and at night around 2 am.
Today we have two better working basal insulins: Levemir and Lantus. Both are designed to work more evenly. You are used to inject the basal insulin in the morning and at night. Thus the Levemir would more fit for your current injection pattern.
Important reminder: this is food for thought. I have read that you are 13 and I recommend to talk with your parents and doctor about these points. Maybe there are reasons why you are using the mix-insulin I am not aware off. Please do not make any changes on your own.