Just be careful mate, the best thing in the first instance is RICE.
I don't want to unduly alarm you, but given what i've went through I don't really see how a physio can say with much certainty that a groin strain is just that. There are a number of interlinking groin / hip conditions, and i think they just start out with the most straighforward, treat that, and if it doesn't heal, move onto the next serious option.
I had a bad experience with an ineffectual/idiotic physio, but the 2nd one i went to was very good.
The other thing you can do after RICE is begin to work hard on your core - pilates and also glute work. A strong core gets all the muscle in that area firing evenly and lessening the risk of overcompensation/overload. A good physio will assess your core as part of considering your groin injury. Needless to say my first physio hadn't a baldy notion about core.
Also, a physio will consider if there is any scar tissue on your adductors which will need to be frictioned off before much recovery can take place.
Good luck