Yes, it is certainly in your interests to make a video statement. As soon as you are able IMO. It's really not as difficult as you might fear. It is just you talking in your own words about what happened. They won't ask you much, they aren't allowed to direct you just to ask specific questions for clarity.
Be prepared that if there are sexual offences they will need to hear as much detail as you can recall. Where, when, what, how, and they may ask questions about consent but that is not because they don't believe you, it's because the issue of consent is going to be brought up in his defence if it ever goes to court and the more that is in the video statement the less you will need to be cross examined over if it goes that far.
If you don't remember anything just say that you don't remember, don't try to guess. They reassured me that was fine.
I found making the video statement very empowering, it was obviously difficult to do, it was helpful that the police did it very quickly after the report and were very good at explaining everything to me beforehand.
Try to ask questions about the CPS's attitudes to charges and general info about the result of that particular force's other similar investigations, timescales, evidence gathering, who you can talk to, what you can say about it, what they plan to do and when in terms of arresting/interviewing him, whether he'll be bailed with or without conditions, other procedural things. If these things are the questions that you'll ponder in the middle of the night (they are for me). I get panic attacks now when the police call because I've had to squash it all down and avoid thinking about it but they rarely call.
I've found the gap after arrest and bail for the investigation to be much harder than the video statement or the report because it has dragged on with no news and considerable anxiety for me.
I've told my ISVA I don't want to see her as having no news and being reminded of it was making it harder - you don't have to see the ISVA/IDVA if that makes things worse, they will be at the other end of the phone for if you need them.
Do whatever works to get you through the statement and investigation. Even if no charges are brought reporting and his arrest will put him into the system and is you advocating for yourself, you don't have any control over whether he will actually face charges or be found guilty because that's not down to whether or not he's done anything wrong but whether there is sufficient proof.
The real benefit you can get is the feeling of empowerment you get from acting in your own best interests and to stand up for yourself by reporting it and supporting the investigation.