How to bulk up without risking diabetes?

Hey! This is my current physique. I train, but inconsistently (about 4 months in total) over the last two years. I know I'm a loser, but one of the main reasons I wasn’t consistent is the diet. It’s really hard to eat enough to hit my surplus/protein needs. So, I used to make this smoothie that was full of sugar (dates, bananas, peanut butter & other stuff). It was too sweet but had 800+ calories, which was really helpful. However, I don’t think it’s healthy to keep it this way. Any tips, please?