Lifestyle tips

So my usual diet (or rather opposite of) consists of the following:
One bag of Donettes for breakfast [1500 calories]
Walmart Chicken Tenders and two sides, and a bottle of coke [1351 calories]
and a variable dinner since most days my parents make it (covid fucked my moving out plans so still not on my own)

What would y'all suggest as something to throw in to add more? I eat this almost every day yet I still seem to struggle with gaining more weight, any suggestions on what to do/add to my diet?

You can always try a milkshake spiked with a high calorie mass gainer right before bed. It helped a friend of mine get past a slow down.

Easiest way I've found is something like an ice cream milkshake with double cream (200ml of cream is about 1000kcal).

However, I found doing this with a traditional blender a pain and ended up getting a 'healthy' smoothie blender. This one also has an ice crusher function so it can be used by others to further justify it.

You can claim this is a dessert if you think your parents will be concerned about consuming something 'unusual', I just said to a family member who gets the stuff discounted that I found a recipe online and like it.

If however you need to be more secretive, then maybe finding something you can snack on or maybe adding an extra meal e.g. when traveling home.

Maybe look at your current pattern for any opportunities, for example, I regularly get coffee from a bakers for my work colleagues but utilize some meal deals to get discounted extra meals e.g. it's £2 for a coffee but and extra £1.30 to add a pizza to it.