A first love can be very powerful however due to lack of maturity, age at the time of falling into love, and lack of experience, there is no way to fairly compare a first love to the love the same person feels for the person they marry. Just as it would be unfair to compare or attempt to categorize the love a person felt for their last partner to the love they feel for you.
Do They Love Me?
If you are receiving what you need from the other, you are loved. If the other person is making effort in the relationship, you are loved. If you feel loved, you are loved, but are you loved enough? Each of us have our own expectations in love and while someone may love you with every fiber of their being, that still may not be enough to make you feel it.
You should ask yourself if your expectations are based upon a lack of giving and receiving, or if you are doing all of the work in the relationship. It could also be that you are carrying baggage from a past relationship where your needs where not met into this current relationship, passing the buck onto your new love.
Open Your Mind and Your Heart
It is also not fair to yourself, or your partner to compare your love for each other to past loves. Seek to discover if the love you are giving one another is strong enough in the here and now, and if it is growing to bring about the result you desire of being together forever.
The only category your love needs to fall in is one of mutual effort, mutual support, and mutual desire to keep that love growing!