I wanna gain weight so bad

Ik ur probably confused like "why would she do that" "dont be ungrateful" or wtv but ill start off by saying when I got broken up with over the summer I unconsciously started starving myself and doomscrolling a lot for a few months. Basically bedrotting majority of my time off of school. And I was considered skinny then, I was 5'6 and about 127Ibs which is good. But now im still 5'6 but im also now 108Ibs. u see the difference? Before I would get supper dizzy sometimes if I skipped a meal and now im dizzy all the time on top of being dehydrated. I lost a total of 19pounds over some bitch. Im trying to gain back my weight and more but bad habits die hard.