I know exactly how you feel, I have a tendency to fantasize about my life in the future when I might girls that I really like (whether it is through tinder or in real life). I've recognised this to be a detriment in my life because it means I come on a little bit too strong (or even desperate!). I'll share my tactics.
Firstly, I'd like to mention that I cannot remove these thoughts entirely, but I do observe them when they come and then employ the tactics.
(1) Meditation, which is a big part of my life- but this might be hard if you haven't practised that much before. For me, meditation means that I am not thinking about anything except for right now.
(2) Distraction: get out, do some exercise, read. I recognise what smallwolf has said- it's an easy thing to say and harder to do. Especially when you would rather be thinking about something else. Might I suggest even doing this instead of replying immediately? Giving yourself time to think of a response (I don't think Tinder has read receipts).
(3) Becoming busy: filling my day with things to do so that I only reply to the girl when I have the time to. Thus, I am only thinking about this girl for a small fraction of my day, and am otherwise focussing on myself.
(4) This comes with being able to recognise when you are fantasizing, and I guess would be classified as CBT. When I recognise I am fantasizing, I tell myself to stop (without deriding myself!) and change my thought pattern. This is to the point where it has become almost habit like to me. Read 'Awaken the Giant Within' by Tony Robbins.
(5) This might be the most controversial one but it works for me. I don't close off avenues of pursuit with other girls when I have found the one that I am interested in. As in- I am still messaging other girls on Tinder, still talking with other girls in real life. This might be similar to distraction, but for me, it reminds me that no matter what happens with this girl that I like, there are still others out there.
Hope this has been helpful!