Identifying a mentor for Fulfulde can feel like an impossible task, particularly for an English speaker. The diaspora tends to migrate to French-speaking countries, and it is not a widely-spoken language to begin with. There are some avenues to explore before losing hope and with some persistence, patience, and flexibility, it is possible to find a Fulfulde mentor.
Personal or Professional Networks
More than likely, if you are interested in studying Fulfulde, it is because you have an existing connection of some kind to the region. Finding a mentor via personal connections is the most likely to yield success in identifying a person with an appropriate background who will (hopefully) stay committed to your language learning.
Alternatively, leverage UW Madison faculty expertise; several faculty in geography, agricultural economics, and political science have connections to the region and may be willing to put you in contact with potential mentors.
RPCVs are generally excited to share the language and culture of the country where they served and will likely be eager to connect you to their friends, and potentially language mentors. Madison has its own RPCV group, but you can find other RPCV groups on Facebook, such as this RPCV Mali group, and request assistance finding a mentor.
Reach out via their website; you never know, they may have a member or know someone who speaks Fulfulde! Even if they do not, the organization has interesting events and resources to explore.
Although I have not personally worked with DLC, it has come recommended through RPCV friends for Fulfulde specifically and I imagine that they would be open to setting up remote language learning sessions.
Professional Interpretation Companies
This suggestion is a bit of a longshot, but some companies may be willing to put you in touch with one of their interpreters or translators. Schreiber Translations, Inc. offers Fula interpretation, but as a large company may not be as responsive. NaTakallam is a small translation/interpretation company which hires refugees and IDPs to serve as their interpreters, and may be able to connect you with a Fulfulde speaker.
What about iTalki?
Unfortunately there are currently no registered Fulfulde (or any dialect) teachers on iTalki.