Don't worry about it. I'm an INxP, a feeler when it comes to my own life, a thinker when relating to the outside world. Believe me, there are pros and cons for every personality type. With thinking (especially in an NT combination) comes detachment; you don't "connect" with your peers, you rarely feel you belong, others definitely don't feel you belong, and your mind never fully relaxes - there's always something in your thoughts that you want to reach, but it stays just outside your grasp. With feeling combined with intuition comes the will to please. You want to belong, and in most ways you do, but you never stop feeling that there's more to it than what you're experiencing. None of these things are fun.
But, on the bright side, a Rational has an entertaining inner life. There are always interesting paradoxes to consider and funny hypothetical scenarios that can produce rather comical outcomes. A Rational with the right amount of mental stimulation will never get bored. An Idealist, on the other hand, often has the most rewarding relationships with friends and significant others, more so than any other group. In that way, as an INFP, your life will likely be more complete than it would if you were an ENTP.
When it comes to how to change types: There are two ways, and none of them are in the least bit recommended. Believe me, I've tried both.
The first one is not something you can control on your own. It requires a severe trauma from the outside; a terrifying moment or period that will either knock you out of your shell so you become hopelessly vulnerable, or knock you further into the shell that was already restraining you. If it hadn't been for certain childhood events, I'd probably be an ENFP. I'm not unhappy with how my personality turned out, but I know my life could be different. In your case, however, it would have been a disaster: You know yourself well enough to understand that you are an INFP, and a trauma of the dimensions I'm describing wouldn't only shake your emotions, but also everything you know and believe in. I'm an agnostic, but if I were to believe in God for a split second, I'd say something along the lines of "and I pray to God you won't have to go through any of that!"
The other way is less dramatic, but possibly even more unhealthy. It involves fooling yourself into believing you are something you're not, and this would leave you with no directions, ambitions or idea of what you are and where you're going. Being a drifter like that is difficult, and it bleeds you dry. No matter how far you go with this method, it will only drain you, and it won't actually make you an ENTP, just a vague image of one that you will be the only one to believe. No fun in that either.
My only advice is to research and check out ways that you can develop and nurture the best qualities of the INFP type; the best way to cope with the personality you have is to work with it and not against it. The most well-developed personalities, the ones that have understood and mastered their type to a T, are usually the happiest ones. That will take work too, but it won't leave you as something you're not, rather help you to be the best you can be.