> (1) I get an erection but goes down during foreplay.

This fact should satisfy any worry you might have of being unable to perform. In other words, there is nothing wrong with your "equipment".

> I get the erection back when my gf is on top and then shortly afterwards have sex.

Based upon what other people have written in the past, I am going to take a leap with this statement and extrapolate that you are of the mindset that a lot of young people have that in order to build toward an orgasmic climax, the route is to jump directly to genital stimulation, or, bypassing even this--intercourse. WRONG!

The process of building sexual desire and arousal is through necking, petting, then advancing to heavy petting, and eventually foreplay--and, spending lots of time engaged in these activities before even getting to genital stimulation by whatever means. Lot's of time means no less than thirty minutes, and more (within reason) is better, particularly for women who require much more time and attention to these details than do randy horny guys who can be read willing and able with little more than a mere thought!

> Am i supposed to have an erection during foreplay?

Yes.

> I love sex but foreplay sucks.

You need to go back to basics and do some reading on the matter of how to arouse each other. Most of the enjoyment comes from spending time cuddling, fiddling, fondling, and caressing each other along with having the necessary emotional connection with the other party to this. If you believe that a lot of genital stimulation of your penis or her pieces-parts is the way to reach an orgasm, you are wrong, even though it will work. Quite literally, this approach has the cart before the horse. You may have heard the new catch-phrase "he's just not that into you", well, devoting 45-60 minutes or more of kissing and caressing each other and whispering sweet nothings is the way to build arousal. Genital stimulation is the means by which we peak or top off an already very high state of "agitation", anticipation, and desire.** I believe if you go back to basics you will have more fun, build more sexual tension and excitement, than if you brush over these important and necessary steps and rush right into having her stroke your penis or accept your penis inside for lots and lots and lots of stroking and thrusting in a hope of acquiring an erection and/or reaching the trigger point of an orgasm. **The correct approach is to already be at a high state of readiness when you begin genital play and intercourse.

> (2) I last about 2/3 minutes during sex. Is this P.E?

Possibly. Premature Ejaculation is generally defined as experiencing an orgasm within the first minute or so. When a climax happens after this period of time it is usually regarded as an ill timed unexpected event. Regardless, the fix for PE and climaxing when not desiring to is the same. I have written about these matters almost daily and at least several times a month. Please do a site search using my name and the terms:
PE
P E
premature ejaculation
exercise
training
squeeze

You should be able to recall one or more of my posts detailing how to achieve and maintain an erection; and, how to prevent having a climax before intending to.

Please read the posts that both Brandye and I have written concerning how to gain control over your orgasms using the training I recommend or the squeeze techniqe she suggests.

Got questions?