How to gain weight in a healthy way?

I am a 29 yr old female mild activity level though I do exercise twice a week for an hour and non cardio 4 days a week for two ten to fifteen minute sessiona. So I believe my calorie count should be around 2100 to 2400. Though not a calorie counter typically I did it for a week and found I typically get 1500 to 1700 Cals a day. I try to eat more but end up feeling stuffed and sluggish and less hungry later.

Here are a few tactics I have tried:
-eat high cal foods like avocado and coconut buts and seeds as well as butters.

-Add flax or chia or hemp to foods to bulk them up.

-Eat heavier nightly meals BC experts encourage the opposite for weight loss

-Juice with high cal items such as almond milk protein powders and or nutritional powders as well as lots of fruit…..