Joystick movement for a rocket or plane.

I want my player to move left and right + a rotation via a joystick or touchscreen object. I want the player to move upwards on its own vertical axis automatically, but slow down and maybe stop moving when I swipe the joystick or touchscreen object down (so I vertically move the joystick down). In my game, I want the player only to be able to move upwards and not be able to go backwards (down on vertical) so the rotation on the player must be limited to a degree, otherwise the player is able to rotate back because the player should always move at least slightly upwards on its own vertical axis. think of the player as a spaceship so there is no gravity.

this is what I have now, but first, what are the problems?
-I can rotate all the way back, so I can go backwards. ( I only want to at least go slightly upwards on the vertical axis).
-the plane sprite I use jitters when I make a turn, the z rotation is frozen if you were wondering.
-I can’t slow the plane down at a public rate of speed, with this same joystick, so I want to be able to move Left, Right and down with the joystick.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;
public class AirPlane : MonoBehaviour
{
[SerializeField]
float moveSpeed = 15f;
[SerializeField]
float angularSpeed = 2f;
float rotationX;
Rigidbody2D rb;

// Use this for initialization
void Start()
{
rb = GetComponent();
}
// Update is called once per frame
void Update()
{
rotationX = CrossPlatformInputManager.GetAxis(“Horizontal”);
transform.Rotate(0, 0, rotationX * angularSpeed);
}
void FixedUpdate()
{
rb.velocity = transform.up * moveSpeed;
}
}

I would really appreciate your help if you could take the time to help me out.

Please reformat your code using tags, otherwise nobody can really read it. Check the first post in the forum for how to do this.

Also, describing game behavior with words can be a bit tricky. If you can find another game and short video capturing exactly the mechanic you describe, or close to it, that would help folks here grasp what you mean.