Vegan

If you search on Google Scholar for scientific articles on the topic, there are indeed several studies and even meta studies out there. I didn't read all of them but only screened some abstracts.

My first impression is that a potential negative effect of soy products seems to be not significant as there are several studies finding no or even the inverse effect. However, if you have certain preconditions don't trust some random guy on the internet. I'd advise to get a second opinion from a doctor and also read through some of the studies in more detail.

The pooled effect size from 10 studies indicated no association between the consumption of a vegetarian diet and depression (pooled effect size: 1.02, 95% CI: 0.84–1.25, p = 0.817). Further, the pooled effect size from four studies suggests that a vegetarian diet is not associated with anxiety (pooled effect size: 1.09, 95% CI: 0.71–1.68, p = 0.678). Due to insufficient data for stress, we were not able to pool the results.

https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=tofu+depression&oq=tofu+depress#d=gs_qabs&t=1725946152211&u=%23p%3DJ2vxLhx2n6AJ

Another study specifically focused on the effect of soy on pregnant or menopausal women. They came to the result that soy products may be even beneficial:

Higher intake of total soy products, tofu, tofu products, fermented soybeans, boiled soybeans, miso soup, and isoflavones was independently related to a lower prevalence of depressive symptoms during pregnancy

However, they also say that they are apparantly the first study with such a result:

Our study is the first to show independent inverse relationships between intake of total soy products, tofu, tofu products, fermented soybeans, boiled soybeans, miso soup, and isoflavones and depressive symptoms during pregnancy.

https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=tofu+depression&oq=tofu+depress#d=gs_qabs&t=1725945759423&u=%23p%3DRX3BHgjfAigJ

Another one regarding depression among workers says...

High intake of isoflavones has been reported to be associated with decreased prevalence of depressive symptoms. However, no prospective study has examined this association [before this study]. [...] During 5065 person-years of follow-up, 276 (23.8 %) workers were newly identified as having depressive symptoms. Isoflavone intake was not associated with risk of depressive symptoms. After adjustment for lifestyle and dietary factors and baseline CES-D score, the multivariable-adjusted hazard ratios (95 % confidence interval) for the lowest through highest tertile of isoflavone intake were 1.00 (reference), 0.93 (0.66–1.31), and 0.93 (0.62–1.38) (P for trend = 0.70). Conclusions Our findings suggest that higher isoflavone intake is not associated with decreased risk of depressive symptoms among Japanese.

https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=tofu+depression&oq=tofu+depress#d=gs_qabs&t=1725946393568&u=%23p%3D_5DnZSJyqMQJ

My search in general: https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=tofu+depression&oq=tofu+depress