It is normal to not make as much progress as you expected in the early stages of a PhD. Most of us look back on the beginning of our PhD as too ambitious, we set high goals and were not able to meet them. If I understand the system you are in (that has coursework during the PhD), you are still at the early stages of a research project. You are still learning the techniques involved in the field, you will produce more results later in your PhD once you master these techniques.
It takes a long time to learn new techniques and how to conduct research on your own. Your advisor should be giving you guidance but you are expected to perform research techniques and learn from the literature on your own. You should still seek help from your advisor or other members of your research group if you are having performing the research techniques, especially if it is replicating existing results which you should be able to reproduce (and troubleshoot). However, a lack of progress or results at the early stages is not something to be concerned about necessarily. Many PhD candidates make up for lost time once they optimise the techniques that they are working with.
Changing research field is challenging. Every project has unique challenges but interdisciplinary projects or those in a new field can be part particularly difficult as there is a lot of background information and techniques to learn. However, you should not be disadvantaged because of this. Every PhD is about developing expertise in a sub-discipline. You are not expected to be an expert in this specific area before you start, you will be learning this during your candidature. By the end of your PhD, you should be more of an expert in the specific topic of your thesis than your advisor, you are exploring a novel topic and devoting more time to it than them.
You should still be able to get guidance from experts in the field but it is your responsibility to take ownership of the topic. Since you chose this topic, I assume that you are still interested in pursuing it if you are able to get the resources and assistance that you need. I think this takes precedence over how it will affect your degree. You can change topic or advisor if the project or environment is not right for you, there are systems in place with most institutions to do this if needed. It will delay your progress but it is an option. However, it may not be necessary in this case. If you want to pursue a career in this field with the experience that you will develop working on your current topic, you can still do that. In the end, only you can decide if you can still work in your current research environment. You should seek the advice of your institution administrators to know what your options are if you are considering changing topic or advisor.
What I think is the fundamental misunderstanding here is that your advisor does not take your concerns seriously. Most PhD candidates in the early stages of their research projects feel that they have not got as much results as they'd planned. It is normal for a project to be challenging but if you genuinely feel that you are out of your depth with this topic or not receiving the guidance that you need, you should make that absolutely clear.
I think the best option in this case is to get a co-supervisor on board with the necessary expertise. This is a very common arrangement, especially when on advisor is an expert or the applications and the other is giving you guidance on the methodology or techniques that you are using. It is a lot easier to involve a co-supervisor as a collaborator at another institution (as an external collaborator) than to change to their research group. Changing institutions is a long process as you need to make sure you meet the requirements of their course and get (partial) credit for what you've done already. It's a lot of paperwork and will delay your progress. It also possible to do an exchange or placement in your collaborator or cosupervisors research group to learn their techniques and gain experience with them. Many institutions have the funds to support such as short-term placement.
It is your personal choice whether to change topic, change advisor, or enter a co-supervisor arrangement. You can bring up any of these with your supervisor or university administrators. Whichever you choose, you must be proactive and transparent. It is your responsibility to ensure that you set goals for your project and that you met them. It is your supervisors to get you the resources and guidance that you need to do that. If they cannot do so themselves they should help to arrange it as they agreed to host you for the project and knew they scope of it beforehand. If you know which researchers would be able to offer you the guidance and techniques that you do not currently have, you should contact them yourself and explain (politely) what the situation is and why you would like them to assist with your project.
Still you do not want to burn bridges or tarnish your relationship with your current advisor, you should voice your concerns clearly and tell them what you considering to do (rather than doing it behind their back without their knowledge). You should show that you are willing to explore your options and find a new topic or (co)supervisor, they should be willing to help you get the help that you need if you can explain clearly why you need it and what you are willing to do to get it. For example, if you need to perform a particular technique with expertise or equipment that your laboratory does not have so you need to work with a collaborator who does this kind of research.
Supervisors are busy and should be supportive of you seeking assistance elsewhere and would rather they remain involved (to some degree) in the project that they've invested time and resources into already. Anything that you can do to get what you need yourself or from a collaborator should be appreciated. This is part of being a proactive researcher in your own capacity and reduces their workload if they are only needed to assist you in their field of expertise. While every student-supervisor relationship is different, most should encourage you to seek help from other places.
