I can understand and relate to your frustration. My mother was an accomplished pianist and taught piano. But when she tried guitar, she gave up quickly. She kept the guitar and so growing up I had access to both instruments. I became enamoured with guitar after starting on piano so I have experience learning both.
The good news is that if you really have the desire to learn to play guitar, and can play piano, there is absolutely no reason you can't develop the ability to play guitar well. But I would suggest that in some respects, learning piano first and then trying to learn guitar, probably makes learning guitar more frustrating than if you had never learned piano in the first place.
Once you learn any instrument you tend to forget how difficult it was in the beginning. In contrast to piano, the guitar involves more physical pain with thin strings on tender finger tips! And each chord on guitar requires you to train your brain to get your fingers and hands to contort into very strange shapes that are completely different from one chord to the next (until you get past the open chords and start learning movable barre chords). Whereas on piano, you can simply move a basic finger alignment up and down the keyboard to play different chords in the key of C (and A minor) with only slight shifts in hand/finger position when black keys come into play.
Another factor involved in guitar that is counterintuitive in the beginning for piano players is the fact that it takes a coordinated action using both hands to play one note or chord on guitar. And the right hand (strumming hand if you are right handed) is responsible for maintaining the rhythm while the left hand is responsible for pressing the correct strings at the right place to make notes and chords. It takes awhile to get used to this, especially after learning piano first where your left and right hand work more independently.
So after learning to play piano, attempting to switch to guitar is potentially more frustrating because of the very different way each instrument is played.
I have a good friend and fellow songwriter who took piano as a child and composed most of her music on piano. As she became more dedicated to her songwriting, she decided to learn guitar so she could present her original music to a wider audience by traveling to open mics, song critiques etc. She gave up after her first attempt but with my encouragement she tried again a year later. Two years after re-starting guitar lessons she is playing guitar better than I am and guitar is my main instrument!
It may have helped that I installed my Custom Finger Friendly String Set for Beginning Guitarist on her guitar to minimize the pain involved in the beginning stages. She found that her background in piano was helpful from a music theory perspective and she had developed finger independence in both hands from playing piano which helped with guitar. Also, playing piano helps develop a sense of timing and rhythm that can translate to guitar. But the logic of the layout of notes on the guitar fretboard vs. piano keyboard was a source of frustration for her in the beginning.
If you really have a strong desire to learn guitar, you can do it (no doubt) but you may have to re-program your thought process and understand that it will take a great deal of deliberate, intentional, dedicated practice to get past the steep learning curve in the very beginning. That is where most aspiring guitarist give up. Piano has a steadier more even learning curve that may actually get steeper as you become more advanced compared to guitar - which has a super steep learning curve in the beginning due to the many factors previously discussed.
So I see your challenge as resigning yourself to the fact that the first 6 months of learning guitar you may not feel you are making the same progress as you did during the first 6 months on piano. And that is probably very frustrating to you! Just accept that as a normal part of learning guitar.
The good news is, that once you get past that initial very steep learning curve and develop the muscle memory to play a few basic chords and get comfortable with some basic right hand rhythm, it gets much much easier to continue to improve your skills on the guitar. If you can just get up that first hill - it's not necessarily down hill from there (still takes regular intentional practice) but it gets so much easier you will feel like it's downhill compared to the very beginning.
Be sure your guitar is set up for optimal playing ease and comfort. Consider starting with lighter strings (click the link above for the most comfortable steel string set available). It would be extremely helpful to take lessons in the beginning from a teacher who can demonstrate proper technique and help you overcome the initial obstacles by showing you more effective ways to do what you might be struggling with. If you can find a teacher that also plays piano, they might be better equipped to understand how to explain how what you must learn to play guitar differs from piano.
Getting from home plate to first base batting left handed versus right handed is the hardest part. Getting the rest of the way around the bases is much the same from one instrument to the other and your piano background will eventually become an asset to your advancement on guitar.
Enjoy your new journey. Just remember - it starts excruciatingly slowly but gets really fun once you get the momentum going! Good luck!