I always have to take the purl loop and with the forefinger and thumb of my right hand and physically loop it over the needle. Is there an easier way?
I'm not sure if you are trying to knit over purls in the previous row (which present themselves as knits in the present row) or if you are talking about trying to knit a stitch that presents itself as a purl in the present row. Either way, I am not sure why the forefinger and thrumb of your right hand has to get involved in doing anything to the "purl loop", which in my mind would be the loop on the LH needle.
Are you saying you do something to the loop on the LH (left hand) needle to do your stitch?
I know how to knit English and Continental and you insert the RH (right hand) needle into the stitch and (in English method) you use the right hand to in some way wrap the RH needle with the yarn to pull the new stitch loop through. I'm not sure what you are doing, but watching the video of how to do the knit stitch
may help. You can watch English and Continental from this page. You can knit into a knit stitch or a purl stitch, but since they are both knit that you are doing, they are done the same way.
Maybe since you are now good at crocheting you would find the Continental method a good technique for you. I have taught several people who were crocheters and they got this method very quickly. But I know some crocheters say they would rather knit English style. Check out the videos and both techniques to see if you can figure out what your problem is and a method that works well for you.
Sometimes we pick up some odd habits when we first learn to knit. Some are actually taught to us by well meaning helpers, and others are our own misinterpretations of what we were taught. It is probably some little thing that is causing the problem, and once you get it straightened out, you will be fine.