When fighting a taller opponent there are several things you can do that in general will help you to close that gap. Sometimes a single thing will work and other times it takes a combination of those things.
First is the distance that you are naturally fighting at. Many fighters fight from to far away to begin with and so that increases the distance that they have to close, giving their opponent more time to see, think, and react to them closing. Fighting from to far away and starting your attacks from to far away creates that extra time for your opponent as well as makes it harder for you to eventually get inside so check that distance and see if you can shorten it by a few or several inches. That can help make a huge difference in all this.
Secondly is foot-work and positioning and you need to be able to change your position quickly and efficiently-more than your opponent can in most cases. If you are not doing any foot-work drills and skipping rope in your training now then you need to start. Increasing your balance, coordination, and ability to move about on your feet better is also sometimes needed in closing that distance more easily against that taller opponent.
Third is this use of fakes and juking your opponent. Next time you spare juke your opponent and he might give away his intentions and if he is considering countering you. A juke and a fake will do this also but you want to use them in combination with your attacks and combinations to create some indecision in your opponent and if they should react or throw things themselves. Watch to see if you can create this indecision and them hesitating to throw or do things and then coordinate your attacks with that time when they seem to be hesitating.
There is also a relaxation phase to this that you can sometimes take advantage of and an example of that is them relaxing to quickly and to much because it was a fake and then attack them while they are relaxing. This is where timing comes in and sometimes you might have to slow things down also just a fraction so that you can catch them relaxing so play with the speed of your execution noting their reactions.
Then there are the use of angles and if you are always attacking straight in from directly in front of them then they only have to counter and throw things straight out in front of them. Instead work on sometimes getting to an angle slightly in respect to them and then attacking, making it harder for them to adjust and counter. They then sometimes have to turn slightly first which will give you more time to close that distance and you might even catch them not reacting at all and hesitating to throw because you are no longer just always attacking straight in.
A lot of times it is a combination of all these things and you using them that will allow you to more easily close the gap, getting in on them where you are fighting at your distance instead of theirs. How well you do all these things and use them can make a huge difference in you being able to close with them even though they are taller.
One last strategy that I would sometimes employ instead when none of this would work as well as I wanted was to instead wait for their attack and give way at an angle slightly and then attack once that angle had been established. Here again timing and footwork are needed for this and you can sometimes catch them as they are coming in or attacking instead and then take advantage of them by countering and staying on the inside with them and doing damage and making them pay for attacking and committing to that attack.
Sometimes with this last aspect you can even get them frustrated and make them over commit because they are missing so much and then when that is happening you should be using those angles and making them pay for missing and over committing. This takes skill and training along with all these other things I have mentioned so you have a lot to work on but if you do then you will start to solve this problem for yourself when fighting a taller opponent.