A strain indicates there was a tear in the muscle of some size and without proper hip flexor strain treatment you could face long term issues. It can be a particularly nasty injury.
All the resources you need to get healthy are on this site, but I will attempt in this post to summarize the main things you need.
Hip Flexor Strain Treatment Resources
The risks of trying to do what you normally do can be pretty high for any serious strain. Minor strains will probably still heal without much issue, but once they get to a certain point you will be triggering substantial scar tissue build up.
Scar tissue is weaker tissue that can be formed fast when your body needs it. So if you’re training or being active while a muscle is torn at all your body will start building scar tissue rapidly as a last resort.
The problem with this is that it’ll prevent healthy muscle from re-forming. What you end up is a weaker hip flexor muscle that will probably get hurt again. Not only that but it won’t be as strong and you might often experience discomfort in the area.
In order to fix scar tissue build-up it takes a conscious effort using deep tissue massage or foam rolling to break down the scar tissue a bit at a time and having enough rest that healthy muscle can now heal in its place.