After reading description the very first thing that came to me is that really easy problem? Then I checked on leetcode and it's medium there.

type Solution struct{}

func (s *Solution) removeNodes(head *ListNode) *ListNode {
    dummy := &ListNode{}
    dummy.Next = head
    
    curr := dummy.Next

    stack := []*ListNode{}
    stack = append(stack, dummy)
    

    for curr != nil && curr.Next != nil {
        next := curr.Next

        for len(stack) != 0 && curr.Val < next.Val {
            prev := stack[len(stack)-1]
            stack = stack[:len(stack)-1]

            prev.Next = next
            curr = prev
        }

        stack = append(stack, curr)
        curr = next
    }

    return dummy.Next
}