issue with speeding up quad set on repeat

So i have a quad with shader set to cutout that acts as a foreground element on an endless runner game. the game is set to speed up after every 100 points which works fine but my quad gets reset every time i hit the points. like on 100 it flickers back to its starting position and speeds up as expected. any ideas how i can make it seamlessly? the code is not anything special to be honest just multiple if statements

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class TextureScroll : MonoBehaviour
6. {
7.     Material backgroundMaterial;
8.     public float scrollSpeed;
9.     public bool scroll = true;
10.     private void Awake()
11.     {
12.         backgroundMaterial = GetComponent<Renderer>().material;
13.     }
14.     // Start is called before the first frame update
15.     void Update()
16.     {
17.        
18.         if (GameManager.score > 100)
19.         {
20.             scrollSpeed = 0.10f;
21.         }
22.         if (GameManager.score > 200)
23.         {
24.             scrollSpeed = 0.12f;
25.         }
26.         if (GameManager.score > 300)
27.         {
28.             scrollSpeed = 0.14f;
29.         }
30.         if (GameManager.score > 400)
31.         {
32.             scrollSpeed = 0.16f;
33.         }
34.         if (GameManager.score > 500)
35.         {
36.             scrollSpeed = 0.18f;
37.         }
38.         if (GameManager.score > 600)
39.         {
40.             scrollSpeed = 0.20f;
41.         }
42.        
43.     }
44.  
45.     private void FixedUpdate()
46.     {
47.         if (scroll)
48.             {
49.                 Vector2 offset = new Vector2(scrollSpeed * Time.time,0);
50.                 backgroundMaterial.mainTextureOffset = offset;
51.             }
52.     }
53. }
54.  

edit i can do it like this adding an acceleration variable for it to speed up over time but i am also trying to figure out how to do it with score too!

Code (CSharp):

1. scrollSpeed += Time.deltaTime * acceleration;

 

I haven't tried this to check, but it looks like the changing of the scrollSpeed variable will cause the offset to suddenly jump.

Would suggest making offset a class variable.
i.e. between lines 9 and 10 add:
Vector2 offset = Vector2.zero;

Then at line 42 add (this ensures the offset is continuously amended rather than suddenly jumping when scroll speed changes):
offset.x+=scrollSpeed*Time.deltaTime;

then remove line 49 as the offset has already been calculated.